A neck mass is a palpable swelling in the neck that may arise from congenital, inflammatory/infectious, or neoplastic causes involving lymph nodes, thyroid, salivary glands, or other cervical structures.

Exam domain	One-glance essentials
Definition / diagnosis	A palpable cervical swelling from congenital, inflammatory or neoplastic disease ^[1] Age, site and duration sharply narrow the differential ^[1]
Epidemiology / risks	Smoking/alcohol and HPV/EBV exposure raise malignant risk ^[1] Recent infection favours reactive nodes but does not exclude cancer ^[1]
Core mechanism	Midline embryologic remnants produce thyroglossal/dermoid masses ^[1] Adult metastatic SCC often presents first as a cervical node ^[1]
Clinical picture	Assess pain, growth, swallowing, voice, otalgia and constitutional symptoms ^[1] Hard, fixed, enlarging or supraclavicular nodes are concerning ^[1]
Investigations	Full oral, pharyngeal, laryngeal, thyroid and skin examination ^[2] Ultrasound and FNA are first-line for many masses; contrast CT maps deep disease ^[2]
Management	Treat the cause rather than the lump ^[3] Persistent adult masses need expedited head-and-neck cancer evaluation ^[3]
Complications	Airway compromise, deep-neck infection and missed malignancy ^[4] Open biopsy can disrupt oncologic planes and seed tumour ^[4]
Prevention / follow-up	Prompt reassessment after any short infection treatment course ^[3] Tobacco/HPV prevention reduces important malignant causes ^[3]
Exam traps	*A persistent adult neck mass is malignant until proven otherwise* ^[2] Avoid empiric repeated antibiotics or open biopsy without specialist evaluation ^[3]

References

^[1] Lecture slides: GC 218. I have a swelling in the neck Neck mass (Notes).pdf

^[2] Lecture slides: GC 218. I have a swelling in the neck Neck mass (Notes).pdf

^[3] Lecture slides: GC 218. I have a swelling in the neck Neck mass (Notes).pdf

^[4] Lecture slides: GC 218. I have a swelling in the neck Neck mass (Notes).pdf

Neck Mass

A neck mass (or "neck swelling"/"neck lump") is any palpable or visible mass in the neck — from the skull base to the clavicle, bounded laterally by the trapezius posteriorly and the midline anteriorly. The term is a presenting complaint, not a diagnosis. It is a common clinical presentation that encompasses a huge range of pathologies — from trivial (reactive lymph node in an URTI) to life-threatening (metastatic squamous cell carcinoma).

"The symptom of a swelling in the neck is a common presentation of many pathologies occurring in the head and neck region. Generally, swellings in the neck may be benign or malignant and in the latter case, primary or secondary." ^[1]

The clinical approach to a neck mass is essentially a triage exercise: Is this congenital vs acquired? If acquired, is it inflammatory/infective or neoplastic? If neoplastic, is it benign or malignant? If malignant, is it primary or metastatic?

2. Epidemiology and Risk Factors

Neck masses are among the most common surgical referrals in otolaryngology and general surgery.
In young patients, lesions are probably congenital; in old patients, they are likely to be malignant. ^[1] This is the single most useful heuristic for the clinical approach.
In children and young adults (< 20 years), the majority of neck masses are inflammatory/infective (reactive lymphadenopathy from URTI, EBV mononucleosis) or congenital (thyroglossal duct cyst, branchial cleft cyst, dermoid cyst, cystic hygroma).
In adults > 40 years, particularly those with risk factors (smoking, alcohol, betel nut), the "malignant until proven otherwise" rule applies — a persistent neck mass > 2–3 weeks in a middle-aged or elderly patient warrants urgent investigation for malignancy.

Smoking — classical risk factor for head and neck squamous cell carcinoma (HNSCC) ^[2]^[3]
Alcoholism — synergism with smoking for HNSCC ^[2]^[3]
HPV infection (Types 16, 18) — HPV-associated H&N cancer occur primarily in the oropharynx including tonsils and the base of tongue ^[3]. Presents in young male patients who have a higher lifetime number of sexual partners and oral sex ^[3].
EBV infection — the primary etiological agent in pathogenesis of NPC ^[2]. Endemic in Southern China including Hong Kong.
Dietary factors — salted fish, preserved or fermented food (contain high levels of nitrosamines) — risk factor for NPC ^[2]
Prior head and neck irradiation — risk factor for thyroid carcinoma and second primary H&N cancers ^[4]
Family history — NPC (certain HLA haplotypes), thyroid carcinoma (MEN2, FAP), lymphoma ^[2]^[4]
Immunosuppression — increases risk for lymphoma
5Ss for oral/oropharyngeal cancer: Smoking + Spirits + Sharp teeth + Sex (male/oral) + Spicy food ^[3]

Hong Kong Context

NPC is endemic in Southern China including HK. A young Chinese man presenting with a neck mass + nasal symptoms + unilateral serous otitis media = NPC until proven otherwise. Always check EBV serology (VCA IgA, EA IgA) and plasma EBV DNA. ^[2]

3. Anatomy and Function

Understanding neck anatomy is essential because the location of the neck mass frequently gives clue to the nature of the neck mass ^[1].

The neck is divided by the sternocleidomastoid (SCM) muscle into two major triangles:

Triangle	Boundaries	Key Contents
Anterior triangle	Anterior: midline; Posterior: SCM; Superior: mandible	Submandibular gland, submental LNs, carotid sheath (common carotid artery, IJV, vagus nerve), thyroid gland, larynx, trachea, pharynx, oesophagus
Posterior triangle	Anterior: SCM; Posterior: trapezius; Inferior: clavicle	Spinal accessory nerve (CN XI), cervical plexus, subclavian vessels, brachial plexus, supraclavicular LNs

The anterior triangle is further subdivided into:

Submental triangle — between the two anterior bellies of digastric
Submandibular (digastric) triangle — floor contains submandibular gland
Carotid triangle — contains carotid bifurcation, carotid body
Muscular triangle — contains thyroid gland, strap muscles, trachea

This is the standardized classification used universally for head and neck surgery and oncology:

Level	Name	Anatomical Boundaries	Common Pathology
Ia	Submental	Between anterior bellies of digastric, above hyoid	Floor of mouth / anterior tongue CA metastasis
Ib	Submandibular	Within digastric triangle	Submandibular gland tumours, oral cavity CA metastasis
II	Upper jugular	Skull base to hyoid, anterior to posterior border of SCM	NPC, oropharyngeal CA, supraglottic laryngeal CA
IIa		Anterior to spinal accessory nerve
IIb		Posterior to spinal accessory nerve
III	Middle jugular	Hyoid to cricoid	Hypopharyngeal CA, laryngeal CA, thyroid CA
IV	Lower jugular	Cricoid to clavicle	Thyroid CA, hypopharyngeal CA, cervical oesophageal CA
V	Posterior triangle	Behind posterior border of SCM	NPC, skin CA, lymphoma
Va		Above inferior belly of omohyoid
Vb		Below inferior belly of omohyoid
VI	Central/visceral compartment	Between carotid sheaths, hyoid to sternum	Thyroid CA (level VI = central compartment nodes)
VII	Superior mediastinal	Below suprasternal notch, in superior mediastinum	Thyroid CA, oesophageal CA

A supraclavicular fossa mass may be secondary deposits from primary malignancies in the gastrointestinal tract. Sometimes patients with a small primary papillary cancer of the thyroid may also present with lower neck lymph nodes metastasis. ^[1]

Why Location Matters

A mass at level II in a young man in Hong Kong → think NPC first (metastatic LN from fossa of Rosenmüller). A mass at level VI → think thyroid pathology. A left supraclavicular node (Virchow's node / Troisier's sign) → think abdominal malignancy (gastric, pancreatic, colorectal) draining via the thoracic duct. A right supraclavicular node → think intrathoracic malignancy (lung, oesophageal).

3.3 Key Structures in the Neck

Level C5–C7 ^[5]. Enclosed by the pretracheal layer of the deep cervical fascia (false capsule) and its own true capsule.
Two lobes connected by isthmus. May have a pyramidal lobe (embryological remnant of thyroglossal duct).
Arterial supply: Superior thyroid artery (from external carotid artery) and inferior thyroid artery (from thyrocervical trunk of subclavian artery). Occasionally, thyroid ima artery from brachiocephalic artery.
Venous drainage: Superior and middle thyroid veins → IJV; inferior thyroid veins → left brachiocephalic vein.
Nerve relations:
- Recurrent laryngeal nerve (RLN): runs in the tracheo-oesophageal groove, close to the inferior thyroid artery. Right RLN loops around the right subclavian artery; left RLN loops around the aortic arch. Injury → hoarseness of voice (vocal cord palsy).
- External branch of the superior laryngeal nerve (EBSLN): runs close to the superior thyroid artery superior pole. Injury → loss of voice projection, inability to hit high notes (denervation of cricothyroid muscle).
Parathyroid glands: 4 glands embedded in or near the posterior capsule of the thyroid. Inadvertent removal → hypoparathyroidism → hypocalcaemia.

The largest salivary gland, located overlying the masseter and ramus of the mandible.
The facial nerve (CN VII) runs through the parotid gland, dividing it into a superficial lobe and a deep lobe. The nerve exits the stylomastoid foramen and branches into: Temporal, Zygomatic, Buccal, Marginal mandibular, Cervical branches.
- Mnemonic: "To Zanzibar By Motor Car"
Parotid duct (Stensen's duct) emerges from the anterior border of the gland, crosses the masseter, pierces the buccinator, and opens into the oral cavity opposite the second upper molar tooth.
Superficial to the gland: greater auricular nerve (sensation to ear lobule — at risk during parotid surgery).

Located in the submandibular (digastric) triangle.
Wharton's duct drains into the floor of the mouth at the sublingual papilla, lateral to the frenulum of the tongue.
Important nerve relations:
- Lingual nerve: runs superficial to the gland, then dips deep to Wharton's duct, then crosses back superficially — "The lingual nerve took a curve, around the hyoglossus; 'Well I'll be damned,' said Wharton's duct, 'the nerve has crossed right over us!'"
- Marginal mandibular branch of facial nerve: runs superficial to the submandibular gland, just deep to the platysma and deep cervical fascia, approximately 1 cm below the mandible (or up to 2 cm below in the elderly). At risk in submandibular gland excision.
- Hypoglossal nerve (CN XII): runs deep to the gland. Injury → ipsilateral tongue deviation towards the lesion side (because the contralateral genioglossus is unopposed).

Contains: common carotid artery (medially), internal jugular vein (laterally), vagus nerve (between/posterior).
Carotid body is located at the carotid bifurcation (approximately at the level of the superior border of the thyroid cartilage). It is a chemoreceptor (senses O₂, CO₂, pH). A carotid body tumour (paraganglioma/chemodectoma) arises from it.

The deep cervical fascia has three layers:

Investing (superficial) layer — encloses SCM and trapezius, also forms the parotid and submandibular gland capsules
Pretracheal (middle) layer — encloses thyroid gland, trachea, oesophagus, strap muscles
Prevertebral (deep) layer — encloses vertebral column, prevertebral muscles, scalene muscles

The retropharyngeal space (between the middle and deep layers) is clinically important because retropharyngeal abscesses can spread inferiorly into the mediastinum (danger space).

4. Etiology (Focus on Hong Kong)

The etiologies of neck masses can be systematically organized. Here is a comprehensive classification:

Condition	Key Features
Thyroglossal duct cyst	Most common congenital midline neck mass. Arises from remnant of thyroglossal duct (tract from foramen cecum of tongue to thyroid). Moves with swallowing AND tongue protrusion (because attached to hyoid via duct remnant). Usually midline, below hyoid. Risk of thyroglossal duct carcinoma (usually papillary). Treatment: Sistrunk procedure (excision of cyst + central portion of hyoid bone + tract up to foramen cecum).
Branchial cleft cyst	Most common lateral congenital neck mass. Second branchial cleft anomaly is most common (> 90%). Located at anterior border of SCM, at junction of upper 1/3 and lower 2/3. May present as cyst, sinus, or fistula.
Dermoid cyst	Midline, submental. Does NOT move with swallowing or tongue protrusion (unlike thyroglossal cyst).
Cystic hygroma (lymphatic malformation)	Transilluminates brilliantly ^[1]. Located in the posterior triangle (often left side). Usually presents in infancy. Can become very large and compromise the airway. Associated with Turner syndrome (45,XO) and Down syndrome.
Vascular malformation	Haemangioma (most common in infancy, often involutes spontaneously), arteriovenous malformation.
Laryngocele	Air-filled herniation of the laryngeal saccule through the thyrohyoid membrane. Increases in size with Valsalva.

Condition	Key Features
Reactive lymphadenopathy	Most common cause of neck mass in children and young adults. Usually secondary to URTI. Tender, mobile, rubbery. Resolves with treatment of infection.
Infective lymphadenitis	Bacterial: often Staphylococcus aureus, Streptococcus. Viral: EBV (infectious mononucleosis), CMV, HIV. Mycobacterial: TB lymphadenitis (scrofula) — common in Hong Kong. Presents as a non-tender, matted lymph node, often with a cold abscess and skin sinus.
TB lymphadenitis (scrofula)	Very important in Hong Kong. Cervical lymph nodes most commonly involved. Caseating granulomas on histology. Ziehl-Neelsen stain for AFB. Culture on Lowenstein-Jensen medium. Treatment: standard anti-TB therapy (RIPE x 2 months + RI x 4 months).
Abscess	Deep neck space infection. Can arise from dental infection, tonsillitis, parotitis. Ludwig's angina = bilateral submandibular space infection → floor of mouth elevation, "hot potato" voice, airway compromise.
Suppurative parotitis ^[6]	Acute infection of the parotid gland. Occurs in the setting of debilitation, dehydration and poor oral hygiene, particularly among the elderly post-operative patients. Most common organism: Staphylococcus aureus ^[6].
Sialadenitis	Inflammation of salivary glands. Obstructive (calculus → 80% in submandibular gland because Wharton's duct is long, upward-draining, and the saliva is more viscous/alkaline) or infective.
Cat-scratch disease	Bartonella henselae. Self-limiting lymphadenopathy.
Toxoplasmosis	Toxoplasma gondii. Painless cervical lymphadenopathy.

Condition	Key Features
Thyroid nodule / Multinodular goitre (MNG)	Very common. Around 10-15% of nodules are malignant ^[5]. Moves with swallowing.
Pleomorphic adenoma	Most common salivary gland tumour. Usually in the parotid (80%). Firm, lobulated, mobile. Mixed tumour (epithelial + myoepithelial + mesenchymal). Risk of malignant transformation if left untreated (→ carcinoma ex pleomorphic adenoma).
Warthin's tumour (papillary cystadenoma lymphomatosum)	Second most common parotid tumour. Bilateral in 10%. More common in males, smokers. "Hot" on Tc-99m pertechnetate scan (unlike most salivary tumours which are "cold").
Lipoma	Soft, non-tender, lobulated. "Slip sign" on palpation. Located in posterior triangle or subcutaneous.
Carotid body tumour (paraganglioma / chemodectoma)	Located at carotid bifurcation. Pulsatile ^[1]. Lateral mobility but no vertical mobility (Fontaine's sign). Splays the internal and external carotid arteries ("lyre sign" on angiography).

Condition	Key Features
Nasopharyngeal carcinoma (NPC)	Predominant tumour type arising in nasopharynx. Frequently originates from pharyngeal recess known as fossa of Rosenmüller. ^[2] Endemic in Southern China including Hong Kong. ^[2] Often presents with neck mass (metastatic LN, usually level II, often bilateral). Other features: epistaxis, nasal obstruction, serous otitis media (due to Eustachian tube blockage), cranial nerve palsies (III-VI, IX-XII) from skull base invasion. Histology: undifferentiated (non-keratinizing) is the most common endemic form in HK, strongly associated with EBV. ^[2]
Thyroid carcinoma	Papillary (85%, lymphatic spread, young), Follicular (10-15%, haematogenous spread to bone and lung, middle age), Medullary (3%, C cells, calcitonin, MEN2), Anaplastic (1%, elderly, very poor prognosis). ^[4]^[5]
Lymphoma	Hodgkin (painless rubbery lymphadenopathy, Reed-Sternberg cells, often in young adults) or Non-Hodgkin (may involve Waldeyer's ring — tonsils and tongue base may be the presenting site for a lymphoma ^[3]).
Salivary gland carcinoma	Mucoepidermoid carcinoma (most common malignant salivary gland tumour, especially in parotid), adenoid cystic carcinoma (slow growth, perineural invasion → pain, distant metastasis to lungs), acinic cell carcinoma.
H&N squamous cell carcinoma	Primary sites: oral cavity, oropharynx, hypopharynx, larynx. 4 Factors for H&N cancer = HPV + EBV + Smoking + Alcoholism ^[3]. May present with a neck mass as the first sign (metastatic LN), sometimes with unknown primary.

Metastatic lymph nodes are the most common cause of a malignant neck mass in adults.
The location of the metastatic LN often gives a clue to the primary site (see Level table above).
Supraclavicular fossa mass may be secondary deposits from primary malignancies in the gastrointestinal tract ^[1]:
- Left supraclavicular (Virchow's) node (Troisier's sign) → intra-abdominal malignancy (stomach, pancreas, colon, ovary) via thoracic duct
- Right supraclavicular node → intrathoracic malignancy (lung, oesophagus)
- Either side → lung, breast
Metastatic thyroid cancer to neck LN: papillary thyroid carcinoma commonly metastasizes to level VI (central compartment) and lateral neck (levels II-IV) ^[4]

Condition	Key Features
Salivary gland calculus (sialolithiasis)	80% submandibular. Presents with recurrent painful swelling of gland, especially at mealtimes (when saliva production increases but cannot drain). Bimanual palpation may reveal a stone in Wharton's duct.
Ranula	Mucocele of sublingual gland. "Plunging ranula" extends through the mylohyoid muscle into the submandibular space → can present as a neck mass.
Ludwig's angina	Bilateral submandibular space infection. Usually odontogenic (2nd/3rd molars have roots below mylohyoid line). Presents with floor of mouth swelling, trismus, drooling, "hot potato" voice. Airway emergency — can cause rapid airway compromise.

5. Pathophysiology (Condition-Specific)

The nasopharynx is a clinically occult site ^[2] — it is located deep and posterior, not easily visible or palpable. The nasopharyngeal mucosa has a rich lymphatic drainage, and the fossa of Rosenmüller is a mucosal recess with numerous lymphoid tissue. Therefore:

The primary tumour grows silently in the pharyngeal recess.
It metastasizes early to cervical lymph nodes (usually level II, bilateral in up to 50% of cases) due to the rich lymphatic network.
Lymph node metastasis are usually present at diagnosis and commonly bilateral ^[2].
Patient will present with locally or regionally advanced disease due to prolonged asymptomatic period or due to missed diagnosis ^[2].

This is why a neck mass + nasal symptoms + unilateral conductive hearing loss (serous otitis media from Eustachian tube blockage) in a Southern Chinese patient = NPC until proven otherwise.

During embryological development, the thyroid gland descends from the foramen cecum at the base of the tongue through the thyroglossal duct to its final position in the anterior neck. The thyroglossal duct normally obliterates but if it persists, a cyst can form anywhere along this tract. The duct is connected to the hyoid bone (it passes through or in front of the hyoid body), and the hyoid is attached to the base of the tongue via the hyoglossus muscle. When the tongue protrudes, it pulls the hyoid forward, which in turn tugs on the thyroglossal duct remnant, causing the cyst to move upward. This distinguishes it from other midline masses.

Three reasons:

Wharton's duct is longer than Stensen's duct (parotid) and has a more tortuous course — longer transit time for saliva.
The duct drains upward (against gravity) — saliva tends to pool.
Submandibular saliva is more viscous and alkaline with a higher mucin and calcium content — this favours stone formation.

The carotid body tumour grows within the adventitia of the carotid artery at the bifurcation. It is tethered to the carotid vessels vertically (along the long axis of the vessels) but can be moved side-to-side (perpendicular to the vessels). This is Fontaine's sign and helps distinguish it from a lymph node (which is mobile in all directions) or a fixed metastatic node (immobile in all directions).

5.5 Pathophysiology of Key Head & Neck Cancers

EBV-driven: EBV infects nasopharyngeal epithelial cells → expression of latent membrane proteins (LMP1, LMP2) → activation of NF-κB and PI3K/Akt signalling → cell proliferation, inhibition of apoptosis, immune evasion.
Nitrosamine co-carcinogens: dietary nitrosamines (from salted fish and preserved food) → DNA adduct formation → genotoxic damage → synergises with EBV to promote carcinogenesis.
Genetic susceptibility: certain HLA haplotypes (HLA-A2, HLA-B46 in Cantonese) → impaired immune clearance of EBV-infected cells.

HPV infection can induce two viral oncoproteins E6 and E7 which inactivate tumour suppressor p53 and Rb leading to tumour promotion ^[3].
E6 protein → binds and degrades p53 (via E6AP ubiquitin ligase) → loss of cell cycle arrest and apoptosis.
E7 protein → binds and inactivates Rb → release of E2F transcription factor → uncontrolled S-phase entry → proliferation.
Define a distinct subset of patients compared with HPV-negative tobacco or alcohol-driven oropharynx cancer with: frequent LN metastasis, higher response rate to induction chemotherapy, better prognosis ^[3].

Type	Cell of Origin	Spread	Key Molecular Alterations
Papillary	Follicular cells	Lymphatic (to level VI)	BRAF V600E mutation (most common), RET/PTC rearrangement
Follicular	Follicular cells	Haematogenous (bone, lung)	RAS mutations, PAX8-PPARγ rearrangement
Medullary	C cells (parafollicular)	Lymphatic	RET proto-oncogene mutation (MEN2A/2B: germline; sporadic: somatic)
Anaplastic	Dedifferentiated follicular cells	Both	TP53 mutations, BRAF, often from dedifferentiation of differentiated carcinoma

6. Classification of Neck Masses

The location, size, consistency, mobility, transillumination, pulsation and tenderness of the swelling are also important features that contribute towards diagnosis. ^[1]

Location	Think of...
Midline	Thyroglossal duct cyst, dermoid cyst, thyroid nodule/goitre, submental lymph node, laryngocele
Lateral – anterior triangle	Lymphadenopathy (reactive/metastatic/lymphoma), branchial cleft cyst, salivary gland (submandibular, parotid), carotid body tumour
Lateral – posterior triangle	Cystic hygroma, lymphoma, metastatic LN (NPC, thyroid CA), spinal accessory nerve schwannoma
Supraclavicular	Metastatic LN (Virchow's node from GIT; lung/breast on either side), lymphoma, subclavian artery aneurysm
Submental	Reactive LN, dermoid cyst, ranula, floor of mouth CA metastasis
Submandibular	Submandibular gland pathology (calculus, sialadenitis, tumour), submandibular LN
Parotid region	Parotid tumour (pleomorphic adenoma, Warthin's, mucoepidermoid CA), parotitis

Lesions occurring in young patients are probably congenital while those in old patients are likely to be malignant. Benign lesions grow slowly while malignant lesions increase in size rapidly. ^[1]

Age Group	Most Likely Etiologies
Children (< 15 years)	Congenital (thyroglossal cyst, branchial cyst, cystic hygroma, dermoid), infective (reactive LN, TB, atypical mycobacterial), lymphoma
Young adults (15-40)	Infective (EBV mononucleosis, TB), congenital, lymphoma, thyroid, NPC
Middle-aged / elderly ( > 40)	Metastatic SCC (H&N primary), thyroid CA, NPC, lymphoma, salivary gland CA

The 80-80-80 Rule for Neck Masses

In adults > 40 years with a neck mass: approximately 80% of non-thyroid neck masses are neoplastic; of these, 80% are malignant; of the malignant ones, 80% are metastatic (rather than primary). This is a useful clinical heuristic.

7. Clinical Features

Symptom	Pathophysiological Basis
Neck swelling/lump	The presenting complaint. Rate of growth matters: benign lesions grow slowly while malignant lesions increase in size rapidly ^[1]. Sudden increase may indicate haemorrhage into a cyst (e.g. thyroid cyst) or rapid tumour growth (anaplastic thyroid CA).
Pain in the neck mass	Inflammation/infection (parotitis, lymphadenitis, abscess), haemorrhage into a cyst, rapid growth in aggressive malignancy (e.g. anaplastic thyroid CA), neural invasion. Note: most malignant masses are initially painless.
Sore throat ^[3]	Pharyngeal tumour (oropharyngeal SCC, tonsillar lymphoma, hypopharyngeal SCC). Also tonsillitis, peritonsillar abscess.
Referred otalgia (ear pain) ^[3]	Shared sensory innervation via CN IX (Jacobson's nerve) and CN X (Arnold's nerve) between the pharynx/larynx and the ear. Pharyngeal tumour → afferent pain via glossopharyngeal/vagal nerve → referred to the ipsilateral ear. This is a RED FLAG for H&N cancer!
Dysphagia / odynophagia ^[3]	Direct tumour mass effect on the pharynx/oesophagus, or extrinsic compression by a large neck mass. Oropharyngeal/hypopharyngeal SCC commonly presents with dysphagia.
Muffled ("hot potato") speech ^[3]	Tumour or abscess in the oropharynx (e.g. tonsillar mass, peritonsillar abscess) causes the palate and tongue base to be displaced, altering resonance.
Hoarseness of voice (HOV)	Recurrent laryngeal nerve involvement (thyroid CA invading RLN, or metastatic LN encasing RLN), or laryngeal carcinoma directly involving the vocal cords. Compression symptoms: dysphagia, SOB (stridor), HOV ^[5].
Stridor / dyspnoea	Extrinsic airway compression (large thyroid goitre, especially retrosternal; deep neck space abscess) or intrinsic tumour (laryngeal CA).
Nasal obstruction / epistaxis	NPC arising in nasopharynx blocks the posterior choana. Tumour vascularity causes epistaxis.
Unilateral serous otitis media / conductive hearing loss	NPC blocks the ipsilateral Eustachian tube opening in the nasopharynx → negative middle ear pressure → serous effusion. In a Chinese adult with unilateral middle ear effusion, always rule out NPC.
Cranial nerve palsies	NPC invading skull base (cavernous sinus: CN III, IV, V1, V2, VI; jugular foramen: CN IX, X, XI; hypoglossal canal: CN XII).
Weight loss, night sweats, fever (B symptoms)	Lymphoma. Constitutional symptoms suggest a systemic malignancy.
Thyrotoxic symptoms (palpitations, tremor, weight loss, heat intolerance, diarrhoea)	Toxic nodule, toxic MNG, or Graves' disease.
Hypothyroid symptoms (fatigue, cold intolerance, constipation, dry skin)	Hashimoto's thyroiditis (most common cause of hypothyroidism in Hong Kong).
Symptoms at mealtimes (pain, swelling of gland with eating)	Salivary duct obstruction (sialolithiasis) — increased saliva production during eating cannot drain past the stone → painful gland distension.
Trismus (inability to open mouth) ^[3]	Tumour infiltrating the pterygoid muscles or masticator space (e.g. advanced oral cavity or oropharyngeal SCC). Also peritonsillar abscess.

Sign	Pathophysiological Basis
Location of neck mass ^[1]	As described above — location gives the best initial clue to aetiology.
Consistency	Cystic (fluid-filled: branchial cyst, thyroglossal cyst, thyroid cyst); Firm-rubbery (lymphoma, reactive LN); Hard (metastatic carcinoma, anaplastic thyroid CA); Soft (lipoma, cystic hygroma).
Mobility	Mobile: benign (reactive LN, lipoma, branchial cyst). Fixed: malignant (metastatic LN fixed to surrounding structures). Carotid body tumour: mobile laterally but not vertically (Fontaine's sign).
Transillumination ^[1]	A mass that transilluminates brilliantly is a cystic hygroma (lymphatic malformation). Thyroglossal and branchial cysts may transilluminate partially. Solid masses do not transilluminate.
Pulsation ^[1]	A pulsatile mass at the carotid bifurcation = carotid body tumour (paraganglioma). Also consider carotid artery aneurysm or arteriovenous malformation.
Tenderness	Suggests inflammation/infection (abscess, sialadenitis, thyroiditis) or haemorrhage into a cyst.
Moves with swallowing	Mass attached to the laryngotracheal complex → thyroid gland pathology (goitre, thyroid nodule, thyroid CA), thyroglossal duct cyst. The thyroid is enclosed by the pretracheal fascia which is attached to the larynx/trachea, so it moves when the larynx moves on swallowing.
Moves with tongue protrusion	Thyroglossal duct cyst — because the duct remnant is connected via the hyoid to the tongue base. This sign distinguishes it from other midline neck masses.
Asymmetrical tonsil ^[3]	Unilateral tonsillar enlargement suggests tonsillar carcinoma or lymphoma (until proven otherwise — must biopsy). Also peritonsillar abscess (quinsy). 50% cervical LN involvement in oropharyngeal tumours ^[3].
Mass / ulcer in oral cavity or pharynx ^[3]	Direct visualization on examination. Oral cavity tumour (floor of mouth, tongue, buccal mucosa), oropharyngeal tumour (tonsil, base of tongue, soft palate).
Facial nerve palsy	Parotid malignancy (especially adenoid cystic carcinoma, mucoepidermoid carcinoma) invading the facial nerve. A parotid mass + facial nerve palsy = malignant until proven otherwise. ^[7]
Horner's syndrome (miosis, ptosis, anhidrosis)	Sympathetic chain involvement — advanced malignancy at the skull base or neck (NPC, Pancoast tumour, cervical metastasis).
Vocal cord palsy	Recurrent laryngeal nerve palsy from thyroid CA, lung apex tumour, oesophageal CA, or metastatic LN in the tracheo-oesophageal groove. Always do flexible nasolaryngoscopy to assess vocal cords before thyroid surgery.
Skin changes over the mass	Erythema (abscess, inflammatory), fungation (advanced malignancy), sinus (TB: caseous discharging sinus), scar (previous surgery).
Retrosternal extension	Large thyroid goitre can extend behind the sternum — assess by percussing over the sternum and noting dullness, or by inability to palpate the lower border of the thyroid (Pemberton's sign: raising both arms above the head causes facial plethora, cyanosis, and distended neck veins due to thoracic inlet obstruction).

Red Flags in a Neck Mass

The following features in a neck mass should prompt urgent investigation for malignancy:

Age > 40 years, especially with smoking/alcohol history
Mass persisting > 2–3 weeks without obvious infective cause
Hard, fixed, non-tender mass
Progressive increase in size
Associated cranial nerve palsy (facial nerve, RLN, skull base)
Referred otalgia with dysphagia/odynophagia
Unilateral serous otitis media in a Southern Chinese adult
Unilateral tonsillar enlargement
Hoarseness of voice > 3 weeks
Weight loss / B symptoms

8. Clinical Approach to a Patient with a Neck Mass

A systematic history should cover:

Mass characteristics: onset, duration, rate of growth, fluctuation in size, pain
Associated symptoms:
- Head & neck: nasal obstruction, epistaxis, hearing loss, otalgia, sore throat, dysphagia, odynophagia, voice change, trismus
- Thyroid: palpitations, tremor, weight change, heat/cold intolerance
- Constitutional: fever, night sweats, weight loss (B symptoms)
- Salivary: relation to meals
Risk factors: smoking, alcohol, betel nut, oral sex (HPV), dietary (salted fish), family history (NPC, thyroid CA, lymphoma), prior radiation, immunosuppression, travel (TB exposure), occupation
Past history: previous malignancy, previous H&N surgery/radiation, dental problems

The location, size, consistency, mobility, transillumination, pulsation and tenderness of the swelling are also important features that contribute towards diagnosis. ^[1]

Inspection: site, size, skin changes (erythema, sinus, ulceration, surgical scars)
Palpation:
- Characteristics: consistency (cystic, firm, hard, rubbery, soft), surface (smooth, lobulated, irregular), tenderness, temperature
- Mobility: in all planes; relation to underlying structures
- Special tests: swallowing test (thyroid/thyroglossal), tongue protrusion (thyroglossal)
Transillumination: cystic hygroma, cystic masses
Auscultation: bruit (carotid body tumour, AV malformation, thyrotoxic goitre)
Complete H&N examination:
- Oral cavity and oropharynx examination ^[3]: look for mucosal lesions, asymmetrical tonsils, floor of mouth swelling
- Anterior rhinoscopy / flexible nasendoscopy: to examine nasopharynx (NPC), larynx (vocal cords)
- Ear examination: otoscopy for middle ear effusion (suggests NPC)
- Thyroid examination: swallowing test, tongue tug test, palpation (diffuse vs solitary nodule vs MNG), cervical LN, trachea position ^[5]
- Cranial nerve examination: particularly CN V, VII, IX, X, XI, XII
General examination: lymphadenopathy elsewhere, hepatosplenomegaly (lymphoma), skin examination (melanoma metastasis)

Examination Pearls

Always examine the oral cavity, pharynx, and larynx in ANY patient presenting with a neck mass. The primary tumour is often hidden in the nasopharynx, oropharynx, or hypopharynx.
A parotid mass must have facial nerve function documented before any intervention.
Every thyroid mass requires vocal cord assessment before surgery.

High Yield Summary

Definition: Any palpable/visible mass in the neck — a presenting complaint, not a diagnosis.

Age rule: Young = likely congenital; Old = likely malignant.

Location rule: Midline → thyroid or thyroglossal duct cyst; Lateral → LN, salivary gland, branchial cyst; Supraclavicular → metastatic (Virchow's node = GIT, right side = thoracic).

80-80-80 rule: In adults > 40, 80% of non-thyroid neck masses are neoplastic; 80% of neoplastic are malignant; 80% of malignant are metastatic.

HK-specific: NPC (EBV-related, endemic), TB lymphadenitis (scrofula), oropharyngeal SCC (HPV-related).

Key physical signs: Transillumination (cystic hygroma), pulsation (carotid body tumour), moves with swallowing (thyroid), moves with tongue protrusion (thyroglossal cyst), facial nerve palsy (parotid malignancy), Fontaine's sign (carotid body tumour).

Red flags: > 40 years, > 2-3 weeks, hard/fixed, associated CN palsy, referred otalgia, unilateral serous otitis media, progressive growth, hoarseness > 3 weeks.

Risk factors for H&N malignancy: Smoking, alcohol, HPV (oropharyngeal), EBV (NPC), salted fish (NPC), prior radiation (thyroid CA).

5Ss for oral/oropharyngeal CA: Smoking, Spirits, Sharp teeth, Sex (male/oral), Spicy food.

Active Recall - Neck Mass (Definition to Clinical Features)

^[1] Lecture slides: GC 218. I have a swelling in the neck Neck mass (Notes).pdf ^[2] Senior notes: felixlai.md (Nasopharyngeal cancer section) ^[3] Lecture slides: GC 219. Infections and tumours in pharynx and oral cavity.pdf ^[4] Senior notes: felixlai.md (Thyroid cancer / etiology section) ^[5] Senior notes: maxim.md (Thyroid section, 9.1) ^[6] Senior notes: felixlai.md (Parotitis section) ^[7] Lecture slides: GC 217. Facial nerve palsy and salivary gland diseases.pdf

Differential Diagnosis of Neck Mass

The differential diagnosis of a neck mass is broad, but it becomes manageable once you anchor your thinking to three axes: age, location, and clinical behaviour (rate of growth, consistency, mobility, etc.). This section lays out a systematic framework.

Swellings in the neck may be benign or malignant and in the latter case, primary or secondary. ^[1]

The first-pass clinical triage:

"The age of the patient and status of the mass since it has been noticed are the two important clues towards the determination of the nature of the mass. Lesions occurring in young patients are probably congenital while those in old patients are likely to be malignant. Benign lesions grow slowly while malignant lesions increase in size rapidly." ^[1]

The neck mass is classified as Benign (1. Congenital, 2. Infective) or Malignant (1. Primary, 2. Secondary). ^[8]

Category	Subcategory	Specific Conditions	Key Distinguishing Features
Congenital	Midline	Thyroglossal duct cyst	Midline, at/below hyoid level. Moves with swallowing AND tongue protrusion. Classically presents when previously unrecognised cyst becomes infected during URTI ^[2]. Mx: Sistrunk procedure (cyst + central hyoid body + tract to foramen cecum) ^[2]^[5]
		Dermoid cyst	Midline, submental. Does NOT move with tongue protrusion. Result of entrapment of epithelium in deep tissue — developmental abnormality or post-trauma ^[2]
		Thymic cyst	Midline or anywhere between angle of mandible and midline — result of implantation of thymic tissue during embryological descent ^[2]
	Lateral	Branchial cleft cyst	Accounts for 20% of paediatric neck mass ^[2]. Presents in late childhood/early adulthood when cyst becomes infected. 2nd branchial cleft cyst is most common — presents inferior to angle of mandible and anterior to SCM; sinus tract opens into tonsillar fossa ^[2]. 1st cleft cyst passes through parotid gland near facial nerve ^[2]. 3rd cleft cyst presents lower in neck, ends at pyriform sinus ^[2]
		Cystic hygroma (lymphatic malformation)	Macrocystic lymphatic malformation. Transilluminates brilliantly ^[1]. Posterior triangle, usually infancy. Associated with Turner syndrome, Down syndrome ^[2]
		Vascular anomalies (haemangioma)	Endothelial neoplasm with increased cellular proliferation → rapid growth then slow regression. Compressible red/bluish soft mass, bruit on auscultation. Usually resolves spontaneously ^[2]
		Laryngocele	Herniation of saccule of larynx through thyrohyoid membrane — air-filled cyst, increases with Valsalva. Hoarseness, cough, foreign body sensation ^[2]
		Ranula	Mucocele from obstruction of sublingual gland. "Plunging ranula" extends through mylohyoid into submandibular space ^[2]
Infective / Inflammatory	Bacterial	Suppurative lymphadenopathy	S. aureus, Strep. pyogenes, M. tuberculosis, Brucellosis, Actinomycosis ^[2]. Tender, warm, fluctuant if abscess
	Viral	Reactive viral lymphadenopathy	URTI (adenovirus, rhinovirus, enterovirus), EBV/CMV mononucleosis, HIV ^[2]. Reassuring features: LN < 1 cm (or < 1.5 cm in upper jugulodigastric chain), oblong shape, preserved vascular hilum, no central hypodensity. Alarming features: fixed and firm LN, LN > 1 cm persisting > 2 weeks after resolution of viral symptoms ^[2]
	Parasitic	Toxoplasmosis	T. gondii — typically acquired through inadequately cooked meat or cat faeces ^[2]
	Mycobacterial	TB lymphadenitis (scrofula)	Tuberculous infection should be suspected in those patients with poor nutritional status ^[1]. Non-tender, matted nodes, cold abscess, caseous discharging sinus. Very important DDx in Hong Kong
	Non-infectious inflammatory	Kimura's disease	Angiolymphoid hyperplasia with eosinophilia. Asian males with eosinophilia and raised IgE. Painless cervical LN or subcutaneous mass without constitutional symptoms ^[2]
		Kikuchi's disease	Histiocytic necrotizing lymphadenitis. Self-limiting, young Asian females. Fever, headache, neutropenia, rash, tender lymphadenopathy ^[2]
		Castleman's disease	Angiofollicular LN hyperplasia. Associated with HHV-8 and POEMS syndrome. Unicentric (usually asymptomatic) → surgical removal. Multicentric (usually symptomatic) → chemotherapy ^[2]
		Rosai-Dorfman disease	Benign inflammatory. Lymphadenopathy + subcutaneous skin lesions/nodules ^[2]
Neoplastic — Benign	Thyroid	Thyroid nodule / MNG	Around 10-15% of nodules are malignant ^[5]. DDx of solitary nodule: dominant nodule in MNG, cyst, adenoma, toxic adenoma, carcinoma. DDx of multiple nodules: MNG, toxic MNG. Diffuse: Graves', Hashimoto's, De Quervain's ^[5]
	Salivary	Pleomorphic adenoma	80% of salivary tumours arise in parotid gland. Parotid tumours are usually benign (80%). Submandibular gland tumours are usually malignant (50%) ^[2]. Firm, lobulated, mobile. Risk of malignant transformation if left untreated
		Warthin's tumour	2nd most common parotid tumour. Bilateral 10%, males, smokers. "Hot" on Tc-99m scan
	Vascular	Carotid body tumour (paraganglioma/chemodectoma)	Pulsatile, bruit on auscultation. Mobile side-to-side but not up-and-down (Fontaine's sign) ^[2]. At carotid bifurcation. Highly vascular, typically benign ^[2]
		Jugulotympanic paraganglioma (glomus jugulare)	May arise following a carotid body tumour ^[2]
	Neural	Schwannoma	Arises from Schwann cells of any peripheral nerve — commonly vagus nerve or superior cervical sympathetic chain in the neck. Vagal schwannoma → hoarseness/aspiration. Sympathetic chain → Horner's syndrome ^[2]
	Soft tissue	Lipoma	Soft, ill-defined, slowly enlarging mass in any location ^[2]. Also epidermoid inclusion cyst, dermoid, pilomatrixoma ^[2]
Neoplastic — Malignant (Primary)	H&N SCC	Metastatic H&N carcinoma	Predominantly metastatic SCC arising from the aerodigestive tract. Masses usually asymptomatic but symptoms related to primary site can be elicited ^[2]. In southern Chinese, when FNA showed undifferentiated SCC, one of the DDx is LN metastasis from NPC. EBV DNA in blood should be checked. If elevated, endoscopic examination and random biopsies of the nasopharynx are indicated. ^[1]
		Oropharyngeal SCC	We are seeing an increasing number of patients with carcinoma of tonsil and tongue base presenting with metastatic neck lymph node. ^[1] Risk factors: smoking, alcohol, oral sex (HPV related) ^[3]. 50% cervical LN at presentation ^[3]
	Thyroid CA	Papillary / Follicular / Medullary / Anaplastic	See thyroid carcinoma table. Palpable neck lumps, rapidly enlarging lumps with pain/HOV/stridor ^[5]^[4]
	Lymphoma	Hodgkin / Non-Hodgkin	Neck involvement common in children with Hodgkin lymphoma (80%). Rubbery, non-tender LN. B symptoms (fever, night sweats, weight loss). When LN is rubbery in consistency and occurs in a young patient, lymphoma should be suspected. Excision of the lymph node is necessary to obtain fresh tissue for pathological examination and staging. ^[1]. Tonsils and tongue base may be the presenting site for a lymphoma ^[3]
	Salivary CA	Mucoepidermoid CA, Adenoid cystic CA, Salivary duct CA, SCC	Malignant subtypes of salivary gland neoplasms ^[2]. Facial nerve palsy with parotid mass = malignant until proven otherwise
Neoplastic — Malignant (Secondary/Metastatic)	Supraclavicular	Virchow's node (left)	Secondary deposits from primary malignancies in the GI tract ^[1]^[8]. Also lung, breast, ovary
		Right supraclavicular	Intrathoracic malignancy (lung, oesophageal)
	Lower neck	Thyroid CA metastasis	Small primary papillary cancer of the thyroid may present with lower neck lymph nodes metastasis ^[1]^[8]
	Metastatic to thyroid	RCC, colorectal, lung, breast, uterine	Renal cell carcinoma is the most common primary to metastasise to thyroid ^[5]

The 50-50 Rule for Salivary Gland Tumours

80% of salivary tumours arise in the parotid, and 80% of those are benign (so parotid → likely benign). But only 50% of submandibular gland tumours are benign — so a submandibular gland mass has a much higher pre-test probability of malignancy. This "rule of decreasing benignity" also applies to minor salivary glands: the smaller the gland, the higher the chance that a tumour arising from it is malignant.

2. Differential Diagnosis by Location

This is the most clinically useful framework because the location of the neck mass frequently gives clue to the nature of the neck mass ^[1].

"Midline neck mass in the lower neck probably arises from the thyroid gland while in the upper neck; thyroglossal cyst is the likely diagnosis." ^[1]

Upper Midline	Lower Midline
Thyroglossal duct cyst	Thyroid nodule (isthmus)
Dermoid cyst	Thyroid goitre
Submental LN (Level Ia)	Thyroid carcinoma
Ranula (plunging)	Pretracheal LN
Thymic cyst	Laryngocele

"Lateral neck mass is more frequently seen than midline mass. Lesions in the upper neck may be salivary glands related. While swellings under the cover of sternomastoid muscle are likely to be lymph nodes." ^[1]

Upper Lateral	Mid/Lower Lateral
Parotid gland pathology (tumour, parotitis)	Lymph node under cover of SCM — inflammatory or neoplastic ^[1]^[8]
Submandibular gland pathology	Branchial cleft cyst (anterior to SCM)
1st branchial cleft cyst	Carotid body tumour (at bifurcation)
Submandibular / jugulodigastric LN	Schwannoma (vagal, sympathetic chain)
Parapharyngeal mass	Cystic hygroma (posterior triangle)

"Supraclavicular fossa mass may be secondary deposits from primary malignancies in gastrointestinal tract. Small primary papillary cancer of the thyroid may present with lower neck lymph nodes metastasis. Other causes of LN enlargement." ^[8]

Left Supraclavicular (Virchow's node)	Right Supraclavicular	Either Side
GIT malignancy (gastric, pancreatic, colorectal, ovarian) — via thoracic duct	Intrathoracic malignancy (lung, oesophageal) — via right lymphatic duct	Lung, breast, lymphoma
Papillary thyroid CA (lower neck LN)	Papillary thyroid CA	TB, reactive

Why left vs right? The thoracic duct drains most of the body (all below the diaphragm + left thorax + left upper limb) and empties into the left subclavian vein at its junction with the left internal jugular vein. Intra-abdominal malignancies therefore drain upward through retroperitoneal → thoracic duct → left supraclavicular node. The right lymphatic duct drains only the right upper limb, right thorax, and right head/neck into the right subclavian/jugular junction.

This is a common examination and clinical scenario, so it deserves its own subsection.

Primary salivary gland tumour ^[2]:

Benign: Pleomorphic adenoma, Monomorphic adenoma, Warthin's tumour, Lymphoepithelioma, Oncocytoma
Malignant: Mucoepidermoid carcinoma, Adenoid cystic carcinoma, Salivary duct carcinoma, SCC

Non-neoplastic DDx of a salivary gland mass ^[2]^[7]:

Salivary cysts
Salivary gland stones (sialolithiasis)
Sjögren's syndrome — autoimmune, bilateral parotid enlargement, dry eyes, dry mouth
Metastasis from other tumours (e.g. scalp SCC, melanoma metastasising to intraparotid LN)
Lymphoepithelial cysts (HIV-associated)
Chronic sclerosing sialadenitis (Kuttner's tumour) — IgG4-related disease, submandibular
Regional lymphadenopathy mimicking a parotid/submandibular mass

DDx of bilateral parotid enlargement ^[2]:

Parotitis (mumps, bacterial)
Bruxism (excess teeth grinding/jaw clenching → masseter hypertrophy mimicking parotid)
Masseter hypertrophy
Sialadenosis — non-inflammatory, non-neoplastic hypertrophy of salivary gland, usually bilateral and painless. Associated with: anorexia/bulimia nervosa (self-induced vomiting), alcoholic cirrhosis, diabetes mellitus ^[2]
Drug-induced (e.g. phenytoin) ^[2]

Red Flag: Parotid Mass + Facial Weakness

Facial weakness in the context of a parotid mass = high suspicion of malignant involvement of parotid gland ^[2]^[7]. Benign parotid tumours (e.g. pleomorphic adenoma) displace the facial nerve but do NOT invade it. A parotid tumour must be distinguished from Bell's palsy ^[2]. Always document facial nerve function before any intervention. Other worrying features of a parotid mass: pain/paraesthesia, mucosal ulceration, rapid growth, skin fixation ^[2].

Around 10-15% of nodules are malignant ^[5]. The DDx depends on whether the patient is hyperthyroid, euthyroid, or hypothyroid:

Presentation	DDx
Solitary nodule	Dominant nodule in MNG; Cyst (true simple cyst, colloid nodule); Neoplastic: adenoma, toxic adenoma, carcinoma ^[5]
Multiple nodules	MNG (hyperplastic/adenomatous nodules with cystic degeneration), toxic MNG; Multiple cysts; Multiple adenomata ^[5]
Diffuse enlargement	Graves' disease; Physiological (pregnancy, puberty); Hashimoto's thyroiditis; De Quervain's/subacute thyroiditis ^[5]

Features suspicious for thyroid malignancy ^[5]:

Rapidly enlarging lump → pain, HOV, stridor
Hard, fixed nodule
Cervical lymphadenopathy
Risk factors: prior neck irradiation, FHx (MEN2, FAP), Hashimoto's (lymphoma), iodine deficiency (follicular CA) ^[4]^[5]

Note: Follicular adenoma is NOT a risk factor of follicular CA ^[5]. This is a common misconception — they are histologically similar but do not have a benign-to-malignant progression pathway.

This is one of the most important clinical scenarios in head and neck surgery.

"When a metastatic cervical lymph node was suspected, then endoscopic examination of the upper aerodigestive tract is mandatory." ^[1]

"Lymph node should be investigated first rather than excised. FNA generally gives a clue to the aetiology of the enlarged lymph node." ^[1]

"Every effort should be spent to locate the primary tumour." ^[1]

The approach is:

FNA of the neck mass — cytology + immunohistochemistry (p16 for HPV, EBER for EBV)
"In southern Chinese, when FNA showed undifferentiated squamous cell carcinoma, one of the DDx is lymph node metastasis from NPC. EBV DNA in blood should be checked. If it is elevated, endoscopic examination and random biopsies of the nasopharynx are indicated." ^[1]
Panendoscopy (direct laryngoscopy + bronchoscopy + OGD) — to examine the entire upper aerodigestive tract and biopsy suspicious areas
Directed biopsies of likely primary sites based on LN level:
- Level II → nasopharynx (NPC), oropharynx (tonsil, tongue base)
- Level III → hypopharynx, larynx
- Level IV → hypopharynx, thyroid, cervical oesophagus
- Level V → nasopharynx, skin (scalp melanoma/SCC)
- Supraclavicular → GIT, lung, breast
Imaging: CT/MRI head and neck, PET-CT if primary still occult
Excisional biopsy of the lymph node is only done as a last resort or when the diagnosis of lymphoma is suspected ^[1]

Why Not Just Excise the Lymph Node?

Excisional biopsy of a suspected metastatic LN is discouraged because it can adversely affect success of subsequent surgical resection by field contamination — tumour cell spillage into the surgical bed makes definitive neck dissection harder and worsens oncological outcome. The one important exception is lymphoma, where excisional biopsy is needed to provide adequate tissue for subtyping (FNA alone is insufficient for lymphoma classification — you need the tissue architecture). ^[1]^[2]

Feature	Think of...	Why?
Age: young patient ^[1]	Congenital, infective, lymphoma	Congenital cysts present in childhood/young adulthood; reactive LN from infections common; lymphoma peaks in young adults
Age: old patient ^[1]	Malignant (metastatic SCC, thyroid CA, salivary CA)	Cumulative exposure to carcinogens (smoking, alcohol, EBV)
Grows slowly ^[1]	Benign (lipoma, pleomorphic adenoma, MNG)	Benign tumours grow by expansion, not invasion
Grows rapidly ^[1]	Malignant (anaplastic thyroid CA, lymphoma, metastatic SCC)	Malignant tumours have uncontrolled proliferation
Transilluminates ^[1]	Cystic hygroma	Thin-walled cyst filled with lymph fluid — light passes through easily
Pulsatile ^[1]	Carotid body tumour	Vascular tumour at carotid bifurcation, transmits arterial pulsation
Rubbery LN in young patient	Lymphoma should be suspected ^[1]	Lymphomatous LN have a characteristic rubbery-firm consistency due to uniform expansion by neoplastic lymphoid cells
Moves with swallowing	Thyroid, thyroglossal cyst	Attached to pretracheal fascia/hyoid → moves with laryngotracheal complex
Moves with tongue protrusion	Thyroglossal duct cyst (only)	Connected to foramen cecum via thyroglossal duct remnant through hyoid
Under cover of SCM ^[1]	Lymph node	Jugular chain LN run along the IJV deep to SCM
Lateral mobility, no vertical mobility	Carotid body tumour (Fontaine's sign)	Tethered vertically to carotid artery, free laterally
Facial nerve palsy + parotid mass	Malignant parotid tumour ^[2]^[7]	Benign tumours displace nerve; malignant tumours invade it
FNA: undifferentiated SCC in Southern Chinese ^[1]	NPC metastasis	Undifferentiated NPC is EBV-driven, endemic in Southern China

High Yield Summary

Primary classification: Benign (Congenital / Infective) vs Malignant (Primary / Secondary).

Location-based DDx:

Midline lower neck → thyroid; upper neck → thyroglossal cyst
Lateral upper neck → salivary gland; under SCM → lymph node
Supraclavicular → metastatic (GIT if left/Virchow's; thoracic if right)

Age-based DDx: Young = congenital/infective; Old = malignant.

Key congenital: Thyroglossal duct cyst (midline, moves with swallowing + tongue protrusion, Sistrunk), Branchial cleft cyst (2nd most common, anterior to SCM, upper 1/3-lower 2/3 junction of SCM), Cystic hygroma (transilluminates brilliantly, posterior triangle).

Key inflammatory (HK): TB lymphadenitis (matted, cold abscess), Kimura's (Asian males, eosinophilia), Kikuchi's (young Asian females, self-limiting).

Key neoplastic: NPC (Southern Chinese, EBV, level II bilateral LN), oropharyngeal SCC (HPV, tonsil/tongue base, 50% cervical LN), thyroid CA (10-15% of nodules malignant), lymphoma (rubbery LN in young → excise for tissue).

Unknown primary approach: FNA first → EBV DNA if undifferentiated SCC in Southern Chinese → panendoscopy → directed biopsy → imaging → excisional biopsy only as last resort or for lymphoma.

Never excise a suspected metastatic LN without attempting to find the primary first (field contamination risk). Exception: lymphoma (need tissue architecture for subtyping).

Active Recall - Differential Diagnosis of Neck Mass

References

^[1] Lecture slides: GC 218. I have a swelling in the neck Neck mass (Notes).pdf ^[2] Senior notes: felixlai.md (Neck mass differential diagnosis section, pp. 200–204) ^[3] Lecture slides: GC 219. Infections and tumours in pharynx and oral cavity.pdf ^[4] Senior notes: felixlai.md (Thyroid cancer / etiology section) ^[5] Senior notes: maxim.md (Thyroid section, 9.1) ^[7] Lecture slides: GC 217. Facial nerve palsy and salivary gland diseases.pdf ^[8] Lecture slides: GC 218. I have a swelling in the neck Neck mass.pdf

Diagnostic Criteria, Diagnostic Algorithm, and Investigation Modalities for Neck Mass

There is no single set of formal "diagnostic criteria" for a neck mass the way there is for, say, rheumatoid arthritis or diabetes. Instead, the diagnosis of a neck mass is a stepwise clinical process that integrates:

Clinical assessment — age, location, clinical features of the mass
Cytological/pathological assessment — FNA, core biopsy, or excisional biopsy
Radiological assessment — imaging to characterise the mass, find a primary tumour (if metastatic), and stage disease

"Diagnosis: age, location & clinical features. Investigation: imaging, FNA, excision. Treatment: nature of pathology." ^[8]

The key concept is that the diagnostic approach varies depending on the clinical suspicion generated by the initial assessment. You do not investigate every neck mass the same way.

The overarching logic:

First, clinically characterise the mass (age + location + features → generate a differential).
Second, do FNA — it is the single most important first-line investigation for most neck masses.
Third, image based on the suspected pathology.
Fourth, if metastatic LN is suspected, find the primary.
Fifth, only excise the node as a last resort (or if lymphoma is suspected).

"Fine needle aspiration cytology is useful in the diagnosis of neck swelling. This should be done for most neck masses and the associated morbidity is low." ^[1]

"Endoscopic examination is an essential part of evaluation of patients with neck mass. When a metastatic cervical lymph node was suspected, then endoscopic examination of the upper aerodigestive tract is mandatory." ^[1]

"Computed tomography or magnetic resonance imaging may give additional clues to the diagnosis of the neck mass such as a neurofibroma or salivary gland tumour. In case of metastatic lymph node, the extent of disease may be determined and this helps the planning of surgery. Angiography or magnetic resonance arteriography is useful when carotid body tumour is suspected." ^[1]

3. Investigation Modalities — Detailed Breakdown

The investigations for a neck mass can be categorised into bedside/blood tests, imaging, and pathological tests. The order matters clinically.

Investigation	When to Order	Key Findings / Interpretation
CBC with differentials ^[2]	All patients	Leukocytosis → infective/inflammatory. Lymphocytosis → viral (EBV mono). Eosinophilia → Kimura's disease, parasitic. Pancytopenia → marrow infiltration (lymphoma, leukaemia). Neutropenia → Kikuchi's disease
Inflammatory markers (ESR, CRP) ^[2]	Suspected infection/inflammation	Elevated in systemic infection, TB, inflammatory conditions. Very high ESR can suggest lymphoma or TB
Blood culture ^[2]	Febrile patients	Identify bacteraemia if deep neck space infection
Tuberculin skin test / IGRA ^[2]	Suspected TB lymphadenitis	Positive TST/IGRA supports TB diagnosis. Note: can be falsely negative in immunosuppressed patients. IGRA (QuantiFERON) more specific (not affected by BCG vaccination)
EBV and CMV serology ^[2]	Young patients, suspected viral, or suspected NPC	EBV VCA IgM → acute infection (mono). For NPC: sustained rise in IgA to both VCA and EA (↑ EBV VCA-IgA and EBV EA-IgA) ^[4]. EBV-specific serological screening has low specificity for NPC but elevated titre may precede diagnosis by up to 10 years ^[4]
Plasma EBV DNA ^[4]	Southern Chinese with undifferentiated SCC on FNA ^[1]	Detected by PCR. Diagnostic and staging evaluation for prognosis. Pre-treatment levels correlate with outcomes. Post-treatment levels evaluate treatment response and detect recurrence ^[4]. If elevated → nasopharyngoscopy + random biopsies of nasopharynx
HIV serology ^[2]	Risk factors present, bilateral parotid cysts, unexplained lymphadenopathy	HIV-associated lymphadenopathy, lymphoepithelial cysts of parotid, increased risk of lymphoma
Autoantibodies (Anti-Ro/SSA, Anti-La/SSB) ^[2]	Suspected Sjögren's syndrome causing periparotid/submandibular masses	Positive → supports Sjögren's diagnosis. Bilateral parotid enlargement + dry eyes + dry mouth
Thyroid function test (TFT) ^[5]^[9]	Routine for all patients with thyroid mass ^[5]	Serum TSH is the most sensitive indicator of thyroid function ^[4]. ↓ TSH → hyperthyroid → consider toxic nodule/MNG → order thyroid scintigraphy. Normal TSH → euthyroid → proceed to USG + FNA. ↑ TSH → hypothyroid → consider Hashimoto's
Serum Ca²⁺ and PO₄³⁻ ^[4]	Thyroid mass, post-thyroidectomy, suspected medullary thyroid CA	Hypercalcaemia → malignancy or co-existing parathyroid hyperplasia (MEN2). Hypocalcaemia → parathyroid compromise
Serum thyroglobulin ^[4]	Differentiated thyroid carcinoma	Baseline tumour marker. Used to monitor recurrence after total thyroidectomy. Anti-thyroglobulin antibodies must be measured simultaneously (can interfere with assay)
Serum calcitonin ^[4]^[5]	Suspected medullary thyroid CA	95% of MTC produces calcitonin ^[4]. Levels > 500 pg/mL suggest metastatic disease → order CT TAP + bone scan ^[5]
Serum CEA ^[4]	Medullary thyroid CA	80% of MTC produces CEA ^[4]. Used alongside calcitonin for monitoring
Genetic testing (RET mutation) ^[4]	All patients with MTC	All MTC patients should be tested for RET mutation. If positive → genetic counselling + family screening for MEN2

Routine Thyroid Investigation Set

Routine for all patients with thyroid nodule: History + Physical exam, TFT, USG thyroid ± FNAC. ^[5] Thyroid scan is ONLY for patients with ↓ TSH (toxic) + nodules. CT is ONLY for retrosternal goitre or locally advanced thyroid cancer. PET scan has no diagnostic role at all in routine thyroid nodule work-up. ^[5]

3.2 Imaging Studies

"Investigations: Fine needle aspiration - cytology. Endoscopic examination: sites of possible primary tumour in the upper aerodigestive tract, biopsy if indicated. Imaging studies: plain x-rays, computed tomography (CT) or magnetic resonance imaging (MRI) or angiography. Positron Emission Tomography (PET)." ^[8]

Why USG first? It is non-invasive, radiation-free, widely available, provides real-time assessment, and can guide FNA. It is the first-line imaging for almost all neck masses.

Roles ^[2]^[5]^[7]:

Confirm origin of mass ^[7] — is it thyroid, salivary gland, lymph node, or something else?
Enlarged neck lymph nodes — number, size, level, sonographic features ^[7]
Stones and dilated ducts — sialolithiasis ^[7]
Thyroid-specific: assess size of goitre, number of nodules, suspicious features, cervical LN (especially deep level VI nodes), retrosternal extension, and guide FNAC ^[5]

Sonographic features suspicious for malignancy in thyroid nodules — Mnemonic: "SHIT CME" ^[5]:

Feature	What it means	Why suspicious
S — Solid nodule	No cystic component	Solid nodules have higher malignancy risk than cystic ones
H — Hypoechoic	Darker than surrounding thyroid tissue	Most thyroid carcinomas are hypoechoic because the densely packed malignant cells reflect less ultrasound
I — Irregular margin	Infiltrative, microlobulated borders	Suggests invasion into surrounding tissue (loss of smooth capsule)
T — Taller than wide	AP diameter > transverse diameter	Growth against tissue planes → aggressive behaviour
C — Chaotic central vascularity	Disorganised blood flow within the nodule	Neoangiogenesis — tumours need new blood supply and it is disorganised
M — Microcalcifications	Tiny punctate echogenic foci without acoustic shadowing	Represent psammoma bodies (especially papillary CA) — laminated calcified structures from tumour cell death
E — Extrathyroidal extension	Tumour extends beyond the thyroid capsule	T4 staging, invading strap muscles, trachea, RLN, oesophagus

Most important features are solid and hypoechoic ^[5]

Sonographic features of malignant lymph nodes ^[4]:

Large > 2 cm
Round shape (taller than wide, loss of the normal oblong/kidney-bean shape)
Heterogeneous, hypoechoic
Loss of central fatty hilum (normal LN have a bright echogenic hilum from hilar fat)
Microcalcification within LN
Intranodal cystic or coagulative necrosis

Sonographic criteria for FNA of thyroid nodules (based on ATA/Bethesda guidelines) ^[4]^[5]:

Sonographic Pattern	USG Findings	Risk of Malignancy	Size Cut-off for FNA
High suspicion	Solid hypoechoic nodule ± ≥1 suspicious feature (microcalcifications, rim calcification with soft tissue extrusion, taller than wide, irregular margins, extrathyroidal extension)	> 70–90%	≥ 1 cm
Intermediate suspicion	Hypoechoic solid nodule WITHOUT microcalcifications, taller than wide, or extrathyroidal extension	10–20%	≥ 1 cm
Low suspicion	Isoechoic or hyperechoic solid nodule, or partially cystic nodule with eccentric solid areas, WITHOUT suspicious features	5–10%	≥ 1.5 cm
Very low suspicion	Partially cystic nodule without suspicious features, spongiform appearance	≤ 3%	≥ 2 cm (or observe)
Benign	Purely cystic nodule	≤ 1%	No biopsy

Note: In practice, all palpable nodules tend to be aspirated regardless of size cut-off ^[5].

USG features: High risk vs Low risk of thyroid cancer ^[4]:

Feature	High Risk	Low Risk
Echogenicity	Hypoechoic	Hyperechoic
Calcifications	Microcalcifications	Large coarse calcifications
Shape	Taller than wide	Wider than tall
Margins/Appearance	Irregular margins, incomplete halo	Spongiform appearance, comet-tail shadowing
Vascularity	Central (chaotic)	Peripheral

Ultrasound is the first-line investigation for salivary gland masses ^[7]:

Confirm origin of mass — is it truly from the parotid/submandibular gland or is it a periparotid LN?
Enlarged neck lymph nodes — metastatic LN from salivary malignancy
Stones — echogenic focus with posterior acoustic shadowing in duct (submandibular > parotid)
Dilated ducts — upstream dilatation proximal to an obstructing stone

When to order CT ^[2]^[5]^[7]:

Retrosternal goitre — cannot be visualised by USG (ultrasound waves do not penetrate bone/sternum), and surgical planning requires knowing extent of retrosternal extension ^[5]
Locally advanced thyroid cancer — delineation of important structures within cervical fascia ^[5]
Characterisation of mass and its relation to normal anatomical structures of H&N ^[2]
Bony invasion — CT is superior to MRI for cortical bone assessment ^[9]
Detection of cervical lymph node metastasis ^[9]
Staging — CT thorax and abdomen for distant metastasis ^[9]
Thyroglossal duct cyst — CT neck with contrast (USG cannot delineate relations with hyoid) ^[5]

For investigation of malignant salivary gland tumour ^[7]:

CT scan: bony invasion, cervical LN ^[7]

When to order MRI ^[2]^[7]^[9]:

Outstanding soft tissue differentiation, lack of ionizing radiation, and relatively infrequent contrast allergy ^[2]
Indicated for masses requiring further definition of soft tissues:
- Infiltrative soft tissue masses ^[2]
- Suspicious malignant perineural spread ^[2] — e.g. adenoid cystic carcinoma of salivary gland tracks along nerves
- Potential CNS origin ^[2]
Imaging modality of choice for cancer of the oral cavity and oropharynx — provides optimal visualization of soft-tissue infiltration ^[9]
Accurate delineation of extent of invasion. May be able to see nerve invasion ^[7]

Key principle: CT is better for bone; MRI is better for soft tissue and perineural invasion. They are complementary, not interchangeable.

When to order PET-CT ^[2]^[7]^[8]:

Identify primary disease when primary is occult after panendoscopy and conventional imaging ^[2]
Detect distant metastatic disease ^[2]^[7]
Workup for distant metastasis of malignant salivary gland tumour ^[7]
NOT a routine diagnostic tool for thyroid nodules ^[5]
Uses ¹⁸F-fluorodeoxyglucose (FDG) — metabolically active malignant cells take up more glucose → "hot" on PET

Angiography or MR arteriography is useful when carotid body tumour is suspected ^[1]
Classic finding: "lyre sign" — splaying of the internal and external carotid arteries by the tumour at the bifurcation (like the arms of a lyre/harp)
Also used for pre-operative embolisation of highly vascular tumours (carotid body tumour, paraganglioma)

Thyroid scan is only ordered in the setting of low TSH (toxic/hyperthyroid) + nodules ^[5] — to determine the functional status of the nodule.

Finding	Interpretation	Clinical Implication
Hot nodule (uptake > surrounding tissue)	Hyperfunctioning, autonomously producing thyroid hormone	Rarely malignant → does NOT require FNA ^[4]
Cold nodule (uptake < surrounding tissue)	Hypofunctioning, not producing thyroid hormone	10–20% risk of malignancy → requires FNA if sonographic criteria are met ^[4]

Why this logic? A hot nodule is autonomously producing thyroid hormone, meaning the cells are functionally differentiated — functional thyroid cells that are actively making thyroglobulin and iodine-trapping are very unlikely to be malignant. A cold nodule has cells that are NOT functioning normally — this may be because they are undifferentiated (malignant) or simply non-functional (colloid cyst, adenoma).

CXR: screening for lung metastasis (NPC, thyroid CA) or primary lung carcinoma causing cervical LN metastasis ^[4]
Bone scan: screening for bone metastasis — particularly for medullary thyroid CA with calcitonin > 500 ^[5], and NPC (bone is the most common distant metastatic site at 75%) ^[4]

"Endoscopic examination is an essential part of evaluation of patients with neck mass. When a metastatic cervical lymph node was suspected, then endoscopic examination of the upper aerodigestive tract is mandatory. Depending on the location of the lymph node, the possible sites of the primary tumour should be carefully examined and biopsied when indicated." ^[1]

Endoscopic Method	When / Why	Key Findings
Flexible nasolaryngoscopy	Office-based. All patients with neck mass + voice change or suspected laryngeal/NPC pathology	Assess vocal cord mobility (RLN palsy), visualise nasopharynx (NPC), laryngeal masses
Nasopharyngoscopy ^[4]	NPC suspected (Southern Chinese, EBV DNA elevated, level II bilateral LN)	Definitive diagnosis is made by endoscope-guided biopsy of primary tumour ^[4]. Random biopsies of nasopharynx if no visible lesion but clinical suspicion high ^[1]
Panendoscopy	Suspected metastatic SCC from aerodigestive tract	Includes direct laryngoscopy + bronchoscopy + OGD. Examines entire upper aerodigestive tract for primary tumour + synchronous second primaries (field cancerisation from shared risk factors — smoking, alcohol)
Examination under anaesthesia (EUA)	When office-based scope is insufficient	Endoscopic examination and/or even examination under anaesthesia should be carried out ^[1]. Allows thorough examination + biopsy of pharynx, larynx, oral cavity

"We are seeing an increasing number of patients with carcinoma of tonsil and tongue base presenting with metastatic neck lymph node. Fine needle aspiration (FNA) is done whenever the diagnosis is suspected." ^[1]

Why panendoscopy? Patients with one H&N cancer (driven by smoking + alcohol) are at high risk for synchronous (within 6 months) or metachronous second primaries elsewhere in the aerodigestive tract (the "field cancerisation" concept — the entire aerodigestive mucosa has been exposed to the same carcinogens). Panendoscopy screens for this.

3.4 Pathological Tests

"Fine needle aspiration cytology is useful in the diagnosis of neck swelling. This should be done for most neck masses and the associated morbidity is low." ^[1]

Method: 21-25G needle, direct palpation or under USG/CT guidance ^[2]
What it provides:
- Cytological analysis — morphology of aspirated cells
- PCR testing for virus: EBV for NPC, HPV for oropharyngeal SCC ^[2]
- Immunocytochemistry (p16 as surrogate for HPV)
What it does NOT provide: does NOT provide material for tissue architecture or immunohistochemical analysis ^[2] — this is why FNA alone is insufficient for lymphoma subtyping (you need tissue architecture to classify Hodgkin vs Non-Hodgkin, and specific subtypes)
Complications: pain, bleeding, false negative ^[5]

FNA for thyroid nodules — Bethesda Classification ^[4]^[5]:

Bethesda Class	Diagnostic Category	Cancer Risk	Recommended Management
I	Non-diagnostic / Unsatisfactory	1–4%	Repeat FNA
II	Benign	0–3%	Clinical follow-up
III	Atypia of undetermined significance (AUS) / Follicular lesion of undetermined significance (FLUS)	5–15%	Repeat FNA (or molecular testing)
IV	Follicular neoplasm / Suspicious for follicular neoplasm	15–30%	Surgical lobectomy (diagnostic hemithyroidectomy)
V	Suspicious for malignancy	60–75%	Surgical lobectomy ± frozen section → total thyroidectomy
VI	Malignant	97–99%	Total thyroidectomy

Why can't FNA distinguish follicular adenoma from follicular carcinoma? Because the difference between them is capsular or vascular invasion — a histological architectural diagnosis that requires seeing the capsule-tumour interface on whole-tissue sections. FNA aspirates individual cells, so you get identical-looking follicular cells from both adenoma and carcinoma. This is why Bethesda IV requires diagnostic lobectomy — you need the entire specimen with capsule intact for the pathologist to assess invasion ^[5].

Provides a tissue core → allows assessment of tissue architecture + immunohistochemistry
Useful when FNA is non-diagnostic or when lymphoma is suspected (intermediate step before excisional biopsy)
Risks: bleeding, nerve injury, tumour seeding ^[2]

"Lymph node should be investigated first rather than excised." ^[1]

"Excisional biopsy of the lymph node is only done as a last resort or when the diagnosis of lymphoma is suspected." ^[1]

Discouraged as first-line because it can adversely affect subsequent surgical resection by field contamination in cases of metastatic carcinoma ^[2]
Indications:
- Lymphoma suspected — excision necessary for fresh tissue for subtyping (flow cytometry, immunohistochemistry on architectural sections) ^[1]
- FNA and core biopsy repeatedly non-diagnostic
- Incision nodal biopsy or nodal dissection should be avoided in NPC since it will negatively impact subsequent treatment ^[4]

FNA vs Excisional Biopsy — When to Use Which

A common exam mistake is to jump straight to excisional biopsy of a neck node. The correct approach:

FNA first for almost everything — low morbidity, gives cytological clue.
If FNA suggests metastatic SCC → find the primary (endoscopy), do NOT excise the node.
If FNA suggests lymphoma or is repeatedly non-diagnostic → excisional biopsy is justified to obtain tissue architecture for subtyping.
If FNA shows undifferentiated SCC in a Southern Chinese patient → check EBV DNA → nasopharyngoscopy. Do NOT excise the node first.

This deserves a separate mention because the lecture emphasises a specific stepwise approach ^[7]:

Modality	Role
Bedside USG ^[7]	Tumour vs inflammation. Location of tumour. Cervical LN.
CT scan ^[7]	Bony invasion. Cervical LN.
MRI ^[7]	Accurate delineation of extent of invasion. May be able to see nerve invasion.
PET-CT ^[7]	Workup for distant metastasis.
FNA / Core biopsy ^[2]	Cytology/histology. Can usually discriminate benign from malignant tumours and metastasis but is less specific in exact tumour type. Tissue diagnosis required before definitive treatment whenever possible.

Investigation	Purpose
CT neck with contrast ^[5]	USG cannot delineate relations with hyoid — CT is needed to show the relationship of the cyst to the hyoid bone and the tract extending to the foramen cecum
USG ± FNAC ^[5]	Confirm presence of normal thyroid gland — this is critical because in thyroid ectopia (lingual thyroid), the thyroglossal duct remnant may contain the only functioning thyroid tissue. Removing it without confirming normal thyroid tissue exists elsewhere → iatrogenic hypothyroidism

4. Specific Diagnostic Algorithms by Clinical Scenario

"When a metastatic cervical lymph node is suspected, endoscopic examination and/or even examination under anaesthesia should be carried out. Every effort should be spent to locate the primary tumour." ^[1]

"In southern Chinese, when fine needle aspiration showed undifferentiated squamous cell carcinoma, one of the differential diagnoses is lymph node metastasis from nasopharyngeal carcinoma. EBV DNA in blood should be checked. If it is elevated, endoscopic examination and random biopsies of the nasopharynx are indicated." ^[1]

Step-by-step:

FNA of the neck node → cytology + immunohistochemistry + viral markers (EBV EBER, HPV p16)
Direct the search by LN level ^[2]:
- Level I or II → Oral cavity, oropharynx, NPC
- Level III or IV → Larynx, hypopharynx, thyroid
- Level II or V → Nasopharynx
- Supraclavicular → GIT, lung, gynaecological sources
Blood: EBV DNA (if Southern Chinese + undifferentiated SCC), TFT (if level VI node)
Endoscopy: Nasopharyngoscopy, panendoscopy with directed biopsies
Imaging: CT or MRI head and neck (extent of disease, surgical planning), CT TAP (distant metastasis), PET-CT (occult primary)
Excisional biopsy — only as last resort, or if lymphoma is suspected

Routine for all patients: TFT, thyroid USG, FNAC ^[5]

TFT → TSH
- If ↓ TSH → thyroid scintigraphy to identify hot/cold nodule
- If normal/↑ TSH → proceed to USG + FNA
USG → characterise nodule (SHIT CME features), assess cervical LN, guide FNA
FNAC → Bethesda classification (I-VI)
CT → only if retrosternal goitre or locally advanced CA thyroid ^[5]
Additional for medullary thyroid CA: calcitonin, CEA, RET mutation testing, 24h urine metanephrines (to rule out phaeochromocytoma in MEN2), Ca/PTH ^[5]

Why Not Thyroid Scan for Everyone?

Thyroid scintigraphy is only useful when you suspect a functioning (toxic) nodule — i.e. when TSH is suppressed. In a euthyroid patient, a thyroid scan adds nothing because you already know the nodule is not autonomously producing hormone. It would be a waste of resources and radiation exposure. The USG + FNA combination is far more informative for cancer risk stratification. ^[5]

Condition	First-Line	Second-Line	Pathological	Special
Reactive LN	Clinical + CBC, CRP	USG if persistent	FNA if alarming features	EBV/CMV serology if viral
TB LN	Tuberculin/IGRA, CXR	USG + FNA for AFB/culture	Excisional biopsy if needed (caseating granuloma)	Anti-TB therapy
Metastatic SCC LN	FNA	Endoscopy (mandatory)	Directed biopsy of primary	CT/MRI, PET-CT, EBV DNA
NPC	EBV VCA-IgA, EBV DNA	Nasopharyngoscopy + biopsy	Histology (WHO classification)	MRI nasopharynx/skull base, PET-CT
Lymphoma	CBC, LDH, β2-microglobulin	CT TAP	Excisional biopsy (not FNA alone)	Bone marrow biopsy for staging
Thyroid nodule	TFT, USG, FNAC	Thyroid scan (if ↓ TSH)	Bethesda classification	CT if retrosternal/locally advanced
Salivary gland mass	USG	CT (bone), MRI (soft tissue/nerve)	FNA/core biopsy	PET-CT (distant metastasis)
Thyroglossal cyst	CT neck with contrast	USG to confirm normal thyroid	FNAC if solid component	—
Branchial cyst	USG, CT/MRI	—	FNA (cholesterol crystals in aspirate)	—
Carotid body tumour	USG (Doppler)	Angiography / MR arteriography	FNA generally avoided (vascular, risk of bleeding)	Pre-op embolisation

High Yield Summary

Investigation triad for neck mass: Imaging + FNA + Excision (only as last resort) ^[8].

FNA is first-line for most neck masses — low morbidity, gives cytological clue. It does NOT provide tissue architecture (cannot subtype lymphoma).

Endoscopy is mandatory when metastatic LN is suspected — examine the entire upper aerodigestive tract (panendoscopy = direct laryngoscopy + bronchoscopy + OGD).

Southern Chinese + undifferentiated SCC on FNA → check EBV DNA → if elevated → nasopharyngoscopy + random biopsies of nasopharynx (r/o NPC).

Thyroid nodule work-up: TFT + USG + FNAC (routine). Thyroid scan only if ↓ TSH. CT only if retrosternal goitre or locally advanced CA.

USG thyroid suspicious features: SHIT CME (Solid, Hypoechoic, Irregular margin, Taller than wide, Chaotic central vascularity, Microcalcifications, Extrathyroidal extension). Most important = solid and hypoechoic.

Bethesda classification: I (non-diagnostic → repeat), II (benign → follow-up), III (AUS → repeat FNA), IV (follicular neoplasm → lobectomy), V (suspicious → lobectomy ± total), VI (malignant → total thyroidectomy).

Hot nodule = rarely cancer (no FNA needed). Cold nodule = 10-20% cancer risk (FNA if sonographic criteria met).

Salivary gland mass investigation: USG first → CT (bone invasion) → MRI (soft tissue/nerve invasion) → PET-CT (distant metastasis).

Never excise a metastatic LN first — find the primary. Excisional biopsy only for lymphoma or as last resort.

Active Recall - Diagnosis and Investigations of Neck Mass

References

^[1] Lecture slides: GC 218. I have a swelling in the neck Neck mass (Notes).pdf ^[2] Senior notes: felixlai.md (Neck mass differential diagnosis and investigations section, pp. 200–206) ^[4] Senior notes: felixlai.md (NPC diagnosis section; Thyroid cancer diagnosis section) ^[5] Senior notes: maxim.md (Thyroid section, 9.1 — investigations, thyroglossal cyst, thyroid cancer) ^[7] Lecture slides: GC 217. Facial nerve palsy and salivary gland diseases.pdf ^[8] Lecture slides: GC 218. I have a swelling in the neck Neck mass.pdf ^[9] Senior notes: felixlai.md (Oropharyngeal cancer diagnosis section)

Management Algorithm and Treatment Modalities for Neck Mass

The management of a neck mass is entirely dictated by the underlying diagnosis. There is no single "treatment of neck mass" — the treatment is the treatment of whatever the mass turns out to be.

"Treatment depends on the nature of the neck mass." ^[1]

"Treatment: nature of pathology." ^[8]

The lecture framework gives us three overarching management themes ^[1]^[8]^[10]:

Congenital lesion in general should be removed surgically at the appropriate age. Their increase in size may lead to functional disturbances. ^[1]^[10]
Lymph node should be investigated rather than excised. For malignant LNs all efforts should be spent to find the primary tumour. ^[10]
Infective lymph nodes should be treated with appropriate antibiotics and this includes anti-tuberculous chemotherapy. ^[1]

And the general management framework for head and neck malignancy ^[3]:

"General principle: Tumour clearance with long term survival benefit. Organ and function preservation." ^[3]

"When surgery is indicated → Resection with adequate margins. Reconstruction for Form and Function. Rehabilitation always — swallowing, voice and hearing." ^[3]

3. Management by Condition Category

"Congenital lesion in general should be removed surgically at the appropriate age. These include cystic hygroma, branchial cyst or thyroglossal cyst. Otherwise these lesions may increase in size leading to functional disturbances later." ^[1]

Condition	Management	Key Surgical Detail	Why?
Thyroglossal duct cyst	Sistrunk operation ^[5]	Remove cyst + duct + whole tract (including body of hyoid bone up to foramen cecum) ^[5] to prevent recurrence. If infected → antibiotics first → then Sistrunk once infection settles	Simple cystectomy has a 50% recurrence rate because the tract remnant persists. The Sistrunk procedure removes the entire tract including the central hyoid body (through which the duct passes), reducing recurrence to < 5%
Branchial cleft cyst	Complete surgical excision of cyst and tract	Must excise the entire fistula tract. 2nd cleft tract extends from anterior to SCM through carotid bifurcation to tonsillar fossa — complete excision can be technically demanding	Incomplete excision → recurrence + recurrent infections
Cystic hygroma	Surgical excision or injection sclerotherapy (e.g. OK-432/picibanil, bleomycin)	May require staged excision for large lesions. Care must be taken to preserve vital structures (nerves, vessels)	Often infiltrates surrounding tissue making complete excision difficult. Sclerotherapy is an alternative for macrocystic lesions
Dermoid cyst	Surgical excision	Midline submental approach	Simple excision is curative
Laryngocele	Surgical excision via external approach (thyrohyoid membrane) or endoscopic	—	Prevents recurrent infections and airway compromise

Thyroglossal Cyst — Confirm Normal Thyroid First!

Before performing a Sistrunk procedure, always confirm the presence of a normal thyroid gland on USG. In rare cases of thyroid ectopia (especially lingual thyroid), the thyroglossal cyst remnant may contain the only functioning thyroid tissue. Removing it without checking → iatrogenic hypothyroidism. ^[5]

Condition	Management	Key Principles
Reactive viral lymphadenopathy	Supportive: analgesics, antipyretics, hydration. Observe for resolution (1–2 weeks post symptom resolution)	If LN persists > 2 weeks after resolution of viral symptoms → investigate further (FNA)
Bacterial lymphadenitis	Empirical antibiotics targeting S. aureus/Streptococcus (e.g. amoxicillin-clavulanate or cloxacillin). If abscess → incision and drainage (I&D)	Suppurative LN may require I&D — antibiotics alone cannot penetrate an abscess cavity effectively
TB lymphadenitis (scrofula)	Anti-tuberculous chemotherapy ^[1]: standard RIPE regimen (Rifampicin + Isoniazid + Pyrazinamide + Ethambutol × 2 months, then Rifampicin + Isoniazid × 4 months). Surgical excision usually not first-line (reserved for diagnostic uncertainty or drug-resistant cases)	Medical therapy is the mainstay. Surgery alone has high recurrence. Nodes may paradoxically enlarge early in treatment (immune reconstitution phenomenon) — this does NOT mean treatment failure
Deep neck abscess ^[3]	Secure airway. Surgical drainage. IV antibiotics. Dental consultation. ^[3]	Airway is the FIRST priority because swelling can rapidly compromise the airway (especially Ludwig's angina, parapharyngeal/retropharyngeal abscess). Dental consultation because the most common source is odontogenic infection
Peritonsillar abscess (quinsy) ^[3]	Definite: Transoral incision and drainage. Antibiotics. Symptomatic: Analgesics. Fluid replacement. Chart I/O. Consider elective tonsillectomy (20% recurrence). ^[3]	Quinsy is drained transorally because the abscess is between the tonsillar capsule and the superior pharyngeal constrictor — easily accessible via the mouth. Interval tonsillectomy is considered because of 20% recurrence risk
Sialadenitis (salivary gland inflammation) ^[7]	Hydration. Sialogogues, massage, heat, antibiotics during acute attacks. Remove stones: exploration of submandibular duct or sialoendoscopy. Excision of the gland (if recurrent/refractory) ^[7]	Conservative measures work by promoting saliva flow to flush the duct. Sialogogues (lemon drops, citric acid) stimulate parasympathetic-mediated salivation. Stones < 5 mm may pass spontaneously. Larger or impacted stones need endoscopic or surgical removal. Gland excision is the definitive option for recurrent disease

Airway First in Deep Neck Infections

The most dangerous complication of a deep neck space infection is airway compromise. Ludwig's angina (bilateral submandibular space infection) can cause rapid floor-of-mouth elevation → airway obstruction. Always secure the airway first — this may require fibreoptic intubation, awake tracheostomy, or surgical airway if intubation is impossible. Only then proceed with I&D and antibiotics. ^[3]

3.3 Benign Neoplasms

Management of a Bethesda II (benign) thyroid nodule follows the 4C indications for thyroidectomy ^[5]:

Cancer (or suspicion of)
Compression (dysphagia, stridor, hoarseness)
Cosmetic concern
Clinically uncontrolled thyrotoxicosis

If none of the 4Cs → observation with clinical + USG monitoring ^[5]

For euthyroid nodules: observe; hemithyroidectomy if 4C. For hyperthyroid nodules: hemithyroidectomy (toxic adenoma) or total thyroidectomy (toxic MNG) ^[5].

Note: Medical therapy with thyroxine suppression for benign nodules is mostly obsoleted ^[5] because: (1) controversial benefits, (2) works in < 20% of patients, (3) significant side effects (iatrogenic thyrotoxicosis, osteoporosis, AF), (4) thyroid gland can regrow after cessation.

Pleomorphic adenoma ^[7]:

"Treatment: complete surgical excision. Parotidectomy with facial nerve preservation. Submandibular gland excision. Wide local excision of minor salivary gland." ^[7]

"Avoid enucleation and tumour spillage." ^[7]

"Consider radiotherapy for recurrent tumour or prevention of recurrence in case of spillage." ^[7]

Why avoid enucleation? Pleomorphic adenoma has an incomplete pseudocapsule with microscopic tumour extensions (pseudopodia) that project through the capsule. Simple enucleation leaves these behind → recurrence rates of 20–45% (compared to < 5% with formal parotidectomy). Additionally, tumour spillage seeds the surgical bed and causes multifocal recurrence, which is much harder to treat.

Warthin's tumour: superficial parotidectomy. Observation is also acceptable for small asymptomatic Warthin's tumours as they are slow-growing and have virtually zero malignant potential.

Surgical excision — subadventitial dissection, separating the tumour from the carotid artery wall
Pre-operative embolisation may be performed 24–48 hours before surgery to reduce intraoperative blood loss (these tumours are highly vascular)
Pre-operative imaging: MR arteriography/CT angiography to assess relationship to carotid vessels, bilateral tumours (10–20% bilateral), and shunt testing
Risk: carotid artery injury → stroke

3.4 Malignant Neoplasms — Head & Neck Cancers

This is the core framework taught in the lecture — learn it well:

"Based on TNM staging. Early stage (I, II): Single modality of treatment — Surgery or radiotherapy alone. Late stage (III, IV): Combined modality of treatment — Concurrent chemo-irradiation. Surgery with adjuvant radiotherapy ± chemotherapy." ^[3]

"General rule: Early stage → radiotherapy or minimally invasive surgery (laser/robotic). Late stage → Surgery with adjuvant treatment." ^[3]

"BUT: Oral cavity and thyroid → surgery in early stage. NPC → chemo-irradiation in late stage." ^[3]

These "BUT" exceptions are critical for exams. Let me explain why:

Oral cavity cancer → surgery first (even early stage): The oral cavity is readily accessible surgically. Radiation to the oral cavity causes significant morbidity (xerostomia, osteoradionecrosis of mandible, dental decay). Surgery allows excellent local control with less long-term morbidity.
Thyroid cancer → surgery first: Differentiated thyroid carcinoma (papillary, follicular) is not particularly radiosensitive to external beam RT. Instead, after surgical resection, radioactive iodine (I-131) can be used for remnant ablation — this relies on the unique ability of thyroid follicular cells to take up iodine.
NPC → chemo-irradiation (not surgery, even in late stage): The nasopharynx is anatomically deep, surrounded by the skull base, internal carotid artery, and cranial nerves — surgical access is extremely difficult and morbid. Additionally, undifferentiated NPC is highly radiosensitive and chemosensitive, making chemo-irradiation the treatment of choice.

Site	Early Stage (I, II)	Late Stage (III, IV)
Oral cavity ^[3]	Surgery (primary surgery is recommended rather than definitive RT ^[9]) ± adjuvant RT if adverse features	Surgery + adjuvant RT ± chemotherapy
Oropharynx ^[3]	RT alone or minimally invasive surgery (TORS — transoral robotic surgery) ^[9]	Concurrent chemoradiation (organ/function preservation, comparable survival to surgery + RT ^[9]) OR Surgery + adjuvant CRT
Larynx	RT alone (voice preservation) or endoscopic laser surgery	Concurrent chemoradiation (larynx preservation) OR Total laryngectomy + adjuvant RT
Hypopharynx	RT alone	Concurrent chemoradiation OR Surgery (laryngopharyngectomy) + adjuvant CRT
NPC ^[3]^[4]	RT only (Stage I) ^[4]	Higher-risk M0: CRT ± induction/adjuvant treatment; M1: systemic treatment ± selected RT. See the version-specific NPC pathway
Thyroid ^[3]	Surgery (hemithyroidectomy or total thyroidectomy based on Bethesda/tumour size)	Total thyroidectomy + RAI ablation ± EBRT

Stage	Approach
Early Stage I	Radiotherapy ONLY
Intermediate Stage II	Concurrent chemoradiotherapy
Advanced Stage III, IVA, IVB	Concurrent chemoradiotherapy ± Adjuvant chemotherapy

Why chemoRT for NPC? Undifferentiated NPC has remarkable sensitivity to both cisplatin-based chemotherapy and radiation. Concurrent delivery exploits the radiosensitising effect of cisplatin (creates DNA crosslinks that impair the tumour cell's ability to repair radiation-induced DNA damage). Adjuvant chemotherapy (e.g. cisplatin + gemcitabine) in advanced stages reduces distant failure rates.

Post-treatment follow-up ^[4]: monitoring with plasma EBV DNA (post-treatment levels evaluate treatment response and detect recurrence), regular nasopharyngoscopy, and imaging.

"Recurrence of the pathologies treated, both benign and malignant. LN treated for unknown primary, the patient should be followed up regularly." ^[8]

Early stage (I, II) oral cavity cancer ^[9]:

Primary surgery is recommended rather than definitive radiotherapy
Selective neck dissection — ipsilateral level I-III or IV for oral tongue cancer > 3mm (Stage I) and most Stage II oral cavity cancers
Bilateral neck dissection if primary tumour is close to or involves the midline
Post-operative radiotherapy if tumour thickness > 4 mm or presence of lymphovascular or perineural invasion

Late stage (III, IV) oral cavity/oropharyngeal cancer ^[9]:

Surgical resection + modified radical neck dissection + post-operative radiotherapy ± concurrent chemotherapy
Concurrent chemoradiation is commonly utilised in advanced stage oropharyngeal carcinoma — effectively preserves function and associated with comparable survival to surgery + post-op RT ^[9]
Definitive RT or CRT for patients who are medically inoperable or have unresectable disease

Oropharyngeal cancer — surgical advances ^[9]:

Transoral robotic surgery (TORS) — minimally invasive approach for oropharyngeal tumour resection
Previously these tumours required a lip-splitting mandibulotomy approach
TORS is associated with shorter hospital stay and patients are less likely to be gastrostomy tube or tracheostomy dependent at 6 months ^[9]
Multidisciplinary approach including swallowing rehabilitation is important ^[9]

Choice of thyroidectomy for differentiated CA thyroid (papillary/follicular) ^[5]:

Hemithyroidectomy: small, low-risk, unilateral tumour (T1-T2, N0, M0) with no adverse features
Total thyroidectomy: T3/T4, bilateral disease, N1/M1, aggressive histology (tall cell, columnar cell, diffuse sclerosing, poorly differentiated), or when RAI ablation is planned

Medullary CA thyroid ^[5]: total thyroidectomy always (because MTC does not take up radioactive iodine, so you cannot rely on RAI for remnant ablation). Prophylactic total thyroidectomy for high-risk MEN2 carriers (RET mutation-positive).

Choice of neck dissection for thyroid cancer ^[5]:

Type	Central Compartment Dissection (Level VI)	Lateral Neck Dissection (Level II-V)
Papillary CA	Therapeutic CCD if central compartment +ve. No prophylactic neck dissection	Therapeutic LCD if lateral compartment +ve
Follicular CA	Usually not required (haematogenous spread, not lymphatic)	Usually not required
Medullary CA	Prophylactic CCD for all patients	Ipsilateral LCD if ipsilateral LN +ve. Bilateral LCD if calcitonin > 200 or contralateral LN +ve

Post-operative adjuvant treatments ^[5]:

Radioactive Iodine Ablation (RAI)	External Beam RT (EBRT)
Pre-op: give rTSH or withdraw T4 to stimulate I-131 uptake + low iodine diet × 1 week	—
Indications: T3/T4 disease, N1/M1 disease, aggressive histology	Positive surgical margins, incomplete resection

Why RAI works: differentiated thyroid cancer cells retain the sodium-iodide symporter (NIS) and therefore can still take up iodine. After total thyroidectomy, any residual thyroid cells (normal or malignant) will concentrate radioactive I-131, which emits β-particles → localised radiation damage → cell death. TSH stimulation (by withdrawing T4 or giving recombinant TSH) upregulates NIS expression, increasing iodine uptake.

Thyroxine replacement and suppression ^[5]:

Dual role: replacement (prevent hypothyroidism) + TSH suppression (high TSH stimulates growth of differentiated thyroid CA via TSH receptors)
Target TSH:
- Low risk → No TSH suppression (0.5–2.0 mIU/L) ^[5]
- Intermediate risk (T3, N1, aggressive histology, vascular invasion) → Low TSH suppression (0.1–0.5 mIU/L) ^[5]
- High risk (T4, M1, incomplete resection) → High TSH suppression ( < 0.1 mIU/L) ^[5]

Mucoepidermoid carcinoma ^[7]:

"Treatment influenced by site, stage, grade. Localised to gland → Excision of gland. Neck node metastasis → Neck dissection. RT for high grade tumour, close margin and extra-glandular spread." ^[7]

Adenoid cystic carcinoma:

Wide surgical excision with attention to perineural margins (this tumour is notorious for perineural invasion — it tracks along nerve sheaths for long distances)
Post-operative RT — especially for advanced disease, close/positive margins, perineural invasion
Tends to have late distant metastasis (especially lung) despite good local control

Carcinoma ex-pleomorphic adenoma ^[7]:

"Treatment: Radical excision. Neck dissection (25% with lymph node involvement at presentation). Postoperative XRT." ^[7] "Prognosis: Dependent upon stage and histology. Usually not very good." ^[7]

This arises from malignant transformation of a longstanding pleomorphic adenoma — hence the importance of excising pleomorphic adenomas rather than observing them indefinitely. The risk of malignant transformation increases with duration (approximately 1.5% per year after 5 years, rising to nearly 10% per year after 15 years).

Facial nerve management in parotid surgery:

Benign tumours: parotidectomy with facial nerve preservation ^[7] — the nerve is carefully dissected and preserved
Malignant tumours: if the nerve is clinically involved (facial palsy pre-operatively or tumour directly invading nerve at surgery) → sacrifice the involved nerve segment → cable nerve graft (e.g. using sural nerve or great auricular nerve)
If nerve is NOT clinically involved → preserve it even in malignancy, and add post-operative RT

Excisional biopsy of the node for subtyping (as discussed previously) ^[1]
Refer to haematology/oncology
Hodgkin lymphoma: ABVD chemotherapy ± involved-field radiation therapy (depending on stage)
Non-Hodgkin lymphoma: variable — R-CHOP for diffuse large B-cell lymphoma (most common), rituximab-based regimens for B-cell subtypes

"For malignant LNs all efforts should be spent to find the primary tumour." ^[10]

If primary is found → treat according to the primary site protocol (surgery, RT, CRT as appropriate) with neck dissection as part of the treatment
If primary is NOT found after panendoscopy + imaging + PET-CT:
- Ipsilateral tonsillectomy (common occult site for HPV-related oropharyngeal SCC)
- RT or CRT to the neck ± likely mucosal sites (nasopharynx, tonsil, tongue base, pyriform sinus)
- Neck dissection if residual disease after RT

"LN treated for unknown primary, the patient should be followed up regularly." ^[8]

Diagnosis	First-Line Treatment	Notes
Thyroglossal cyst	Sistrunk operation	Confirm normal thyroid on USG first. Antibiotics first if infected.
Branchial cleft cyst	Complete surgical excision	Must excise entire tract to prevent recurrence
Cystic hygroma	Excision or sclerotherapy	May need staged procedures for large lesions
Reactive LN	Observation, treat underlying infection	Investigate if persistent > 2 weeks
TB LN	Anti-TB therapy (RIPE)	Medical mainstay; surgery rarely needed
Deep neck abscess	Secure airway + Surgical drainage + IV antibiotics + Dental consult	Airway FIRST
Peritonsillar abscess	Transoral I&D + Antibiotics. Consider interval tonsillectomy	20% recurrence
Sialadenitis	Hydration, sialogogues, massage, antibiotics. Remove stones. Gland excision if refractory.	—
Benign thyroid nodule	Observation. Surgery only if 4C	Thyroxine suppression obsoleted
Pleomorphic adenoma	Parotidectomy with FN preservation. Avoid enucleation/spillage.	RT for recurrence or spillage
Carotid body tumour	Surgical excision ± pre-op embolisation	MR angiography pre-op
NPC Stage I	RT only	EBV DNA monitoring post-treatment
NPC Stage II-IV	Concurrent chemoRT ± adjuvant chemo	Cisplatin-based
Oral cavity CA (early)	Surgery + selective neck dissection ± adjuvant RT	Surgery is first-line for oral cavity
Oropharyngeal CA (early)	RT alone or TORS	HPV+ has better prognosis
H&N CA (late stage)	Surgery + adjuvant CRT or Concurrent CRT	Organ preservation approach for oropharynx/larynx
Differentiated thyroid CA	Total/hemithyroidectomy ± RAI ± thyroxine suppression	Based on risk stratification
Medullary thyroid CA	Total thyroidectomy + prophylactic CCD	No RAI (C cells don't take up iodine)
Mucoepidermoid CA	Gland excision ± neck dissection ± RT	Based on site, stage, grade
Carcinoma ex-pleomorphic adenoma	Radical excision + neck dissection + post-op XRT	Poor prognosis
Lymphoma	Excisional biopsy → chemotherapy ± RT	ABVD (Hodgkin), R-CHOP (DLBCL)
Metastatic LN (known primary)	Treat primary site + neck dissection	—
Metastatic LN (unknown primary)	Panendoscopy → tonsillectomy → RT/CRT to neck ± mucosal sites	Regular follow-up

"EARLY REFERRAL to ENT Surgeons when suspecting malignancy: Persistent 2–4 weeks after conservative/empirical treatment. Clinically suspicious: irregular, induration, > 2 cm, associated cervical LN enlargement." ^[3]

This is the practical take-home: if you are a GP or a non-surgical clinician and you see a neck mass that is:

Persistent > 2–4 weeks despite conservative treatment
Clinically suspicious (irregular, indurated, > 2 cm, associated cervical LN)
In a patient with risk factors (smoker, alcohol, Southern Chinese, > 40 years old)

→ Refer urgently to ENT surgery. Do NOT watch and wait.

High Yield Summary

Management is dictated by diagnosis: congenital → surgery; infective → antibiotics (TB = anti-TB chemo); benign neoplasm → excision if symptomatic/4C; malignant → stage-dependent multimodality.

H&N cancer management framework:

Early stage (I, II): single modality — surgery or RT
Late stage (III, IV): combined modality — concurrent chemoRT or surgery + adjuvant CRT
Exceptions: Oral cavity and thyroid → surgery in early stage. NPC → chemoRT in late stage.

NPC: RT only for Stage I; concurrent chemoRT ± adjuvant chemo for Stage II-IV.

Thyroid cancer surgery: total thyroidectomy if T3/T4, N1/M1, aggressive histology, or planned RAI. Hemithyroidectomy for small low-risk tumours. RAI for remnant ablation (T3/T4, N1/M1). Thyroxine with TSH suppression based on risk.

Salivary gland tumours: pleomorphic adenoma → parotidectomy with FN preservation, AVOID enucleation/spillage. Mucoepidermoid CA → gland excision ± neck dissection ± RT. Carcinoma ex-pleomorphic adenoma → radical excision + neck dissection + post-op XRT.

Thyroglossal cyst: Sistrunk procedure (cyst + central hyoid + tract to foramen cecum). Confirm normal thyroid exists first.

Deep neck abscess: AIRWAY FIRST → surgical drainage → IV antibiotics → dental consult.

4C indications for thyroidectomy: Cancer, Compression, Cosmetic, unControlled thyrotoxicosis.

Referral criteria: persistent > 2-4 weeks, irregular/indurated, > 2 cm, associated cervical LN → early ENT referral.

Active Recall - Management of Neck Mass

References

^[1] Lecture slides: GC 218. I have a swelling in the neck Neck mass (Notes).pdf ^[3] Lecture slides: GC 219. Infections and tumours in pharynx and oral cavity.pdf ^[4] Senior notes: felixlai.md (NPC treatment section) ^[5] Senior notes: maxim.md (Thyroid section — thyroglossal cyst, thyroid cancer management, thyroidectomy indications) ^[7] Lecture slides: GC 217. Facial nerve palsy and salivary gland diseases.pdf ^[8] Lecture slides: GC 218. I have a swelling in the neck Neck mass.pdf ^[9] Senior notes: felixlai.md (Oropharyngeal cancer treatment section) ^[10] Lecture slides: GC 218. I have a swelling in the neck Neck mass.pdf (Treatment slide)

Complications of Neck Mass Conditions and Their Treatments

Complications related to neck masses can be organised into two broad categories: (A) complications of the underlying pathology itself (what happens if you do NOT treat, or the disease progresses) and (B) complications of treatment (surgery, radiation, chemotherapy). Both are high-yield for exams.

1. Complications of the Underlying Pathology

"Congenital lesion in general should be removed surgically at the appropriate age. Otherwise these lesions may increase in size leading to functional disturbances later." ^[1]

Condition	Complications if Untreated	Pathophysiological Explanation
Thyroglossal duct cyst	Abscess (tenderness, fever), fistula formation, malignant transformation to papillary CA (rare) ^[5]	The cyst is lined by thyroid epithelium → susceptible to infection (especially during URTI when organisms track from foramen cecum); chronic inflammation can lead to fistula to skin; the thyroid epithelium retains malignant potential (papillary CA in < 1% of cases)
Branchial cleft cyst	Recurrent infections, fistula tract to skin, pharyngeal oedema → airway and swallowing disorders ^[2]	Cyst communicates with pharyngeal remnants → recurrent seeding from pharyngeal flora; chronic inflammation causes fistula formation
Cystic hygroma	Progressive enlargement → airway compromise, feeding difficulty, cosmetic deformity	Lymphatic malformation does not involute spontaneously (unlike haemangioma). Can enlarge rapidly with intercurrent URTI or haemorrhage into the cyst

Disease	Complications of Progression	Why?
NPC	Skull base invasion → CN III-VI palsies (cavernous sinus), CN IX-XII (jugular foramen/hypoglossal canal). Distant metastasis: bone (75%), liver, lung ^[4]	NPC grows from nasopharynx superiorly into skull base foramina
Oral cavity / Oropharyngeal SCC	Airway obstruction (tumour bulk), haemorrhage (erosion into vessels), aspiration pneumonia, malnutrition (dysphagia/odynophagia), fistula formation	Direct local invasion into muscles, mandible, carotid sheath
Thyroid carcinoma	Tracheal invasion → stridor, oesophageal invasion → dysphagia, RLN invasion → hoarseness, distant metastasis (bone/lung in follicular CA; LN in papillary CA)	Local structures immediately adjacent to thyroid gland
Lymphoma	Superior vena cava syndrome (mediastinal mass), tumour lysis syndrome (with treatment), B symptoms, organ infiltration	Bulky lymphadenopathy compressing vascular structures
Deep neck abscess (untreated)	Airway obstruction, mediastinitis (retropharyngeal abscess tracks into mediastinum via danger space), IJV thrombosis (Lemierre's syndrome), sepsis, necrotising fasciitis	Fascial planes of the neck are continuous with the mediastinum; the retropharyngeal space extends from skull base to T4 level

2. Complications of Treatment

2.1 Complications of Thyroidectomy

This is the single most important complication set to know for neck mass management because thyroid surgery is so common.

Complication	Mechanism	Clinical Features	Management
Intraoperative bleeding	Injury to superior/inferior thyroid artery or thyroid veins	Haemorrhage in surgical field	Intraoperative haemostasis, ligation
Oesophageal injury	Direct injury during dissection (especially posteriorly)	Post-op dysphagia, mediastinitis if unrecognised	Primary repair, drain, antibiotics
Tracheal injury	Direct surgical injury	Air leak, surgical emphysema	Primary repair
Tracheomalacia ^[5]	Floppy tracheal wall due to chronic compression by longstanding goitre → cartilage rings weaken and soften over time	Post-extubation stridor and airway collapse	May require prolonged intubation, tracheostomy, or tracheal stenting
Thyroid storm ^[4]	Develops in patients with longstanding untreated hyperthyroidism precipitated by acute event such as surgery, trauma or infection. Rapid ↑ in serum thyroid hormone → increased response to sympathetic inputs from catecholamine by permissive effect	Hyperpyrexia, tachycardia, hypertension → heart failure with hypotension and arrhythmia ^[4]	β-blocker (propranolol), thionamide (carbimazole/PTU), Lugol's iodine, hydrocortisone, cooling, supportive ICU care
Superior laryngeal nerve (SLN) injury ^[4]	SLN supplies the cricothyroid muscle which lengthens (tenses) the vocal cord to produce high-pitched sound — the external branch of SLN runs close to the superior thyroid artery at the upper pole	Vocal fatigue and changes in voice quality ^[4], loss of high pitch, poor volume, easy fatigue ^[5]	Usually observed; voice therapy. Prevention: careful identification of EBSLN during superior pole ligation
Recurrent laryngeal nerve (RLN) injury ^[4]	RLN supplies all intrinsic muscles of larynx except cricothyroid — runs in tracheo-oesophageal groove near inferior thyroid artery	See table below	See table below

RLN injury — detailed breakdown ^[4]^[5]:

	Partial injury (irritation)	Complete injury
Unilateral	Hoarseness	Hoarseness (vocal cord in paramedian position)
Bilateral	Airway obstruction (6 adductors > 2 abductors) — the adductor muscles (which close the cords) are more numerous and powerful than the sole abductor (posterior cricoarytenoid), so with partial/irritative bilateral injury, the cords tend to adduct → airway compromise	Hoarseness: stay in anatomical position (i.e. mid-open) — complete denervation means no muscle tone at all, both cords fall to the cadaveric (intermediate) position → airway patent but voice very breathy ^[5]

Why is bilateral partial injury paradoxically more dangerous than bilateral complete injury? With partial injury, the adductor muscles (thyroarytenoid, lateral cricoarytenoid, interarytenoid — 6 muscles total) are partially innervated and spasm, overpowering the posterior cricoarytenoid (the only abductor, 2 muscles) → cords approximate → airway obstruction → emergency. With complete bilateral transection, ALL muscles are paralysed → cords rest in the cadaveric mid-open position → airway is compromised but not completely obstructed (patient can breathe, though voice is very weak).

Management of vocal cord palsy ^[5]: Cord medialisation procedures — e.g. injection thyroplasty, open thyroplasty (Gortex) for unilateral palsy. Bilateral adductor spasm may require emergency tracheostomy followed by later cordotomy or arytenoidectomy.

Complication	Mechanism	Clinical Features	Management
Reactionary haemorrhage ^[5]	Reactionary bleeding within first 24h post-op → haematoma compresses on venous return → laryngeal oedema → complete closure of vocal cord → asphyxiation ^[5]	Neck swelling, tachycardia, stridor, respiratory distress	Remove ALL stitches from skin down to cervical fascia at bedside (FIRST action!) → Resuscitation: protect airway, give supplemental oxygen → Arrange emergency operating theatre (EOT) for haemostasis ^[5]
Wound infection	Contamination during surgery	Erythema, swelling, purulent discharge, fever	Antibiotics, drainage if abscess. (Note: wound infection is NOT a commonly recognised complication of thyroidectomy because it is a clean surgical field ^[5])

Post-Thyroidectomy Neck Haematoma — An Emergency!

A post-thyroidectomy haematoma is a life-threatening emergency. The key mechanism is: bleeding → haematoma under the strap muscles and deep cervical fascia → venous congestion (the veins are thin-walled and compress before arteries) → laryngeal oedema → airway obstruction → death. The first action is to open ALL stitches at the bedside — from skin sutures down to the deep cervical fascia — to release the compressing haematoma. This can be done by any doctor, nurse, or even a medical student in an emergency. Do NOT wait for the operating theatre. Then protect the airway and arrange EOT for formal haemostasis. ^[5]

Complication	Mechanism	Clinical Features	Management
Hypoparathyroidism → Hypocalcaemia	Most common complication of total thyroidectomy ^[4]^[5]. Inadvertent removal, devascularisation, or bruising of parathyroid glands → ↓ PTH → ↓ serum Ca²⁺. Only in total thyroidectomy ^[5] (hemithyroidectomy has < 1% risk because contralateral glands are untouched)	Perioral numbness, carpopedal spasm, Chvostek's sign, Trousseau's sign ^[4]^[5]. Severe hypoCa can lead to laryngospasm requiring emergency intubation / surgical airway ^[5]	Acute: IV calcium gluconate (10–20 mL of 10% over 10 min — slow bolus) ^[4]. Replacement: Calcium carbonate + Calcitriol (Vitamin D) ^[4]. Routinely check Ca on post-op Day 1 ^[5]
Hungry bone syndrome ^[4]	Rapid, profound hypocalcaemia due to sudden drop in PTH, causing rapid deposition of Ca into demineralised bone ^[5]. Occurs in patients with pre-existing hyperparathyroidism or thyrotoxicosis with bone disease — after gland removal, the suppressed normal parathyroids cannot compensate, and avid osteoblast activity "sucks" calcium into bone	Severe symptomatic hypocalcaemia, often refractory to standard calcium replacement	Aggressive IV calcium infusion, calcium + vitamin D supplementation ^[5]
Hypothyroidism	After total thyroidectomy (100% require replacement) ^[5] or subtotal thyroidectomy (variable)	Fatigue, cold intolerance, weight gain, constipation	Lifelong levothyroxine (T4) replacement
Recurrence	Incomplete excision of malignant tissue, or new disease	New neck mass, rising thyroglobulin (differentiated CA) or calcitonin (MTC)	Re-investigation (USG, FNA, imaging), revision surgery, RAI
Hypertrophic scar / keloid ^[4]	Abnormal wound healing in the anterior neck (Kocher incision is cosmetically sensitive)	Raised, thickened scar	Silicone sheets, steroid injection, revision if severe

Post-op dyspnoea after thyroidectomy — differential diagnosis ^[5]:

Haemorrhage: hypovolaemic shock, laryngeal oedema from compression
Bilateral RLN irritation causing adductor spasm → airway obstruction
Laryngeal spasm due to hypocalcaemia
Injury to trachea / pneumothorax
Tracheomalacia (floppy tracheal wall from chronic compression)

This is an excellent structured answer for an OSCE/exam question asking "What are the causes of post-thyroidectomy stridor?"

Neck dissection involves removing cervical lymph nodes (selective, modified radical, or radical). The complications depend on which structures are preserved or sacrificed ^[4]^[11].

Complication	Mechanism	Clinical Features	Management
Spinal accessory nerve (CN XI) injury	CN XI traverses the posterior triangle and runs through/near level II and V nodes. Radical neck dissection intentionally sacrifices it; modified radical preserves it but it can still be injured	Shoulder drop, inability to abduct arm above 90° (trapezius weakness), "winging" of scapula	Physiotherapy; nerve grafting if transected
Internal jugular vein (IJV) sacrifice	Radical neck dissection removes IJV	Facial and cerebral oedema (especially if bilateral); risk of raised ICP if bilateral IJV ligation	Avoid bilateral radical dissection simultaneously
Sternocleidomastoid (SCM) sacrifice	Radical neck dissection removes SCM	Cosmetic defect (loss of neck contour), decreased neck rotation strength	Reconstructive options; modified radical avoids this
Chyle leak / chylothorax	Thoracic duct injury (left side, level IV/Vb dissection — thoracic duct enters at junction of left subclavian and IJV)	Milky drainage from wound drain; high output can cause nutritional depletion, immunosuppression	Conservative: NPO + TPN + octreotide. Surgical re-exploration with ligation if high output ( > 1 L/day) or persistent
Seroma	Disruption of lymphatics → serous fluid collection ^[11]	Swelling under the flap, fluctuant	Drain insertion or percutaneous aspiration ^[11]
Haemorrhage / haematoma	Injury to carotid, jugular, or branches	Neck swelling, airway compromise	Emergency exploration
Wound infection	Post-operative contamination	Erythema, fever, discharge	Antibiotics, I&D if abscess
Marginal mandibular nerve injury	Runs superficial to submandibular gland, within level Ib dissection zone	Ipsilateral lower lip droop (cannot depress lower lip, asymmetric smile)	Usually transient (neuropraxia); permanent if transected
Hypoglossal nerve (CN XII) injury	Runs deep to submandibular gland, can be injured in level I-II dissection	Ipsilateral tongue deviation towards the lesion (unopposed contralateral genioglossus), difficulty with speech and swallowing	Usually permanent if transected; speech therapy
Phrenic nerve injury	Rare; runs on anterior surface of scalenus anterior in the posterior triangle	Ipsilateral diaphragmatic paralysis → raised hemidiaphragm on CXR, dyspnoea	Usually observed; diaphragmatic plication if symptomatic
Horner's syndrome	Sympathetic chain injury (runs prevertebral, deep in the neck)	Miosis, ptosis, anhidrosis (ipsilateral)	No treatment; permanent

Modified radical neck dissection preserves one or more of: IJV, CN XI, SCM. Radical neck dissection removes all. Both have the same recurrence rates but modified radical has much lower morbidity. Radical is only performed when there is evidence of invasion into these structures. ^[4]

Complication	Mechanism	Clinical Features	Management
Facial nerve injury	CN VII runs through the parotid gland dividing it into superficial and deep lobes. Despite careful dissection, neuropraxia (temporary) is common; transection (permanent) is rare in benign surgery	Ipsilateral facial weakness (brow, eye closure, mouth — depending on branch injured). Marginal mandibular branch is most vulnerable	If neuropraxia: observation (recovery over weeks-months). If transected: primary repair or cable nerve graft (sural nerve, great auricular nerve). Adjuncts: eye care (lubricant, taping) if unable to close eye
Frey syndrome (auriculotemporal syndrome / gustatory sweating) ^[2]	Aberrant regeneration of cut parasympathetic fibres between the otic ganglion and salivary tissues → innervation of sweat glands and subcutaneous vessels instead of salivary gland ^[2]	Sweating and flushing of facial skin over parotid bed and neck during mastication ^[2]	Conservative: antiperspirant. Medical: botulinum toxin injection (blocks cholinergic nerve terminals to sweat glands). Surgical: interpositional barrier (e.g. acellular dermal matrix) between nerve stumps and skin
Great auricular nerve injury	Great auricular nerve crosses the SCM and provides sensation to the ear lobule; it is the most commonly injured nerve in parotid surgery	Numbness of ear lobule (ipsilateral)	Usually permanent; no treatment
Salivary fistula / sialocele	Leakage of saliva from cut parotid tissue or duct stump	Swelling that increases at mealtimes, clear fluid drainage from wound	Pressure dressing, repeated aspiration, anticholinergic (glycopyrrolate). Rarely requires re-operation
Tumour recurrence	Incomplete excision (especially if enucleation was performed instead of formal parotidectomy)	New mass in parotid bed	Revision surgery ± RT; multifocal recurrence after spillage is very difficult to manage

Frey Syndrome — Why Does Eating Make You Sweat?

During parotid surgery, the parasympathetic secretomotor fibres to the parotid gland (carried by the auriculotemporal nerve from the otic ganglion) are inevitably cut. During healing, these parasympathetic fibres regenerate but aberrantly — instead of growing back to salivary acini, they grow into the skin and innervate sweat glands and subcutaneous blood vessels. When the patient eats (which normally stimulates parasympathetic salivation), the misdirected fibres instead trigger sweating and flushing over the parotid region. It's a classic example of aberrant nerve regeneration. ^[2]

Radiation to the head and neck causes significant acute and late toxicity:

Timing	Complication	Mechanism	Management
Acute	Radiation dermatitis	Direct radiation damage to skin basal layer	Moisturiser, steroid cream if severe
	Mucositis (oral/pharyngeal)	Radiation kills rapidly dividing mucosal epithelial cells → ulceration, pain	Analgesics, mouthwashes, PEG feeding if severe
	Dysphagia / odynophagia ^[9]	Mucosal inflammation and oedema	Dietary modification, analgesia, PEG tube
	Hoarseness ^[9]	Laryngeal oedema	Observation, voice rest
Late	Xerostomia (dry mouth)	Radiation damage to salivary glands (especially parotid — serous acini are very radiosensitive)	Saliva substitutes, pilocarpine (muscarinic agonist to stimulate residual gland), IMRT (intensity-modulated RT) to spare parotid
	Osteoradionecrosis (ORN) of mandible	Radiation damages osteocytes and vasculature of mandible → hypovascular, hypocellular, hypoxic bone → cannot heal after minor trauma (e.g. tooth extraction)	Prevention: dental clearance BEFORE RT. Treatment: hyperbaric oxygen, antibiotics, debridement, free flap reconstruction if severe
	Radiation-induced fibrosis / trismus	Fibrosis of masticator muscles (masseter, pterygoids)	Jaw physiotherapy (TheraBite device), pentoxifylline + vitamin E
	Hypothyroidism	Radiation to thyroid gland	TFT monitoring, thyroxine replacement
	Second primary malignancy	Radiation-induced DNA damage in surrounding normal tissue	Long-term surveillance
	Dental caries	Xerostomia → loss of saliva's protective buffering and antimicrobial action → rampant caries	Fluoride trays, meticulous dental hygiene

Cisplatin is the backbone of H&N chemotherapy (especially for NPC, concurrent chemoRT). Key toxicities:

Toxicity	Mechanism	Management
Nephrotoxicity	Cisplatin is excreted renally and causes direct tubular damage (proximal tubular necrosis)	Aggressive IV hydration pre- and post-infusion, monitor Cr, avoid concomitant nephrotoxins
Ototoxicity	Damage to cochlear hair cells (outer hair cells most susceptible) → irreversible sensorineural hearing loss (high frequency first)	Audiometric monitoring, dose adjustment
Nausea / vomiting	Highly emetogenic — triggers chemoreceptor trigger zone (CTZ)	5-HT₃ antagonist (ondansetron) + NK1 antagonist (aprepitant) + dexamethasone
Myelosuppression	Direct bone marrow toxicity	FBC monitoring, G-CSF if needed, dose adjustment
Peripheral neuropathy	Sensory axonal neuropathy from platinum-DNA adducts in dorsal root ganglion neurons	Dose-dependent; gabapentin/pregabalin for symptom management

Surgery	Specific Complication	Why?
Sistrunk procedure	Recurrence (if incomplete excision of tract or hyoid), hypothyroidism (if normal thyroid not confirmed pre-op), wound infection	Tract extends from cyst through hyoid to foramen cecum — miss any part → recurrence
Branchial cyst excision	Recurrence, injury to nearby structures (carotid vessels, CN X, CN XII, CN XI for 2nd cleft; facial nerve for 1st cleft)	2nd cleft tract passes between internal and external carotid arteries and near CN X/XII
Cystic hygroma excision	Recurrence (infiltrative margins), nerve injury, haemorrhage, incomplete excision	Lymphatic malformation insinuates between normal structures

"Recurrence of the pathologies treated, both benign and malignant. LN treated for unknown primary, the patient should be followed up regularly." ^[8]

Condition	Surveillance Protocol
Differentiated thyroid CA	Neck USG every 6 months; TSH + thyroglobulin every 3 months ^[5]. Post-RAI whole body scan at 1 week (screen for residual) and at 6–12 months (screen for recurrence) ^[4]
Medullary thyroid CA	Calcitonin + CEA levels for monitoring; neck USG; CT TAP + bone scan if calcitonin rising ^[4]
NPC	EBV DNA levels for treatment response and recurrence detection; regular nasopharyngoscopy; imaging ^[4]
Oral/oropharyngeal SCC	Regular clinic visits with oral examination, flexible nasolaryngoscopy; CT/MRI + PET-CT as indicated
Pleomorphic adenoma	Long-term follow-up for recurrence (can recur even 10–20 years later) and malignant transformation
Unknown primary (treated)	Regular follow-up ^[8] — the primary may declare itself years later

High Yield Summary

Thyroidectomy complications (must know):

Immediate: bleeding, thyroid storm, SLN injury (loss of high pitch), RLN injury (unilateral → hoarseness; bilateral partial → airway obstruction; bilateral complete → breathy voice but airway open)
Early: Reactionary haemorrhage → open ALL stitches at bedside first! Haematoma → venous congestion → laryngeal oedema → asphyxiation
Late: Hypoparathyroidism → hypocalcaemia (MOST common complication) — perioral numbness, carpopedal spasm, Chvostek's, Trousseau's, laryngospasm. Mx: IV calcium gluconate then oral Ca + calcitriol. Also: hypothyroidism, recurrence, scar.

Post-thyroidectomy stridor DDx: haemorrhage, bilateral RLN irritation, hypocalcaemic laryngospasm, tracheal injury/pneumothorax, tracheomalacia.

Bilateral RLN paradox: partial bilateral injury → adductor spasm → airway obstruction (6 adductors overpower 2 abductors). Complete bilateral injury → cadaveric position → patent airway but poor voice.

Parotid surgery: facial nerve injury (neuropraxia common, transection rare), Frey syndrome (gustatory sweating from aberrant parasympathetic regeneration), great auricular nerve injury (ear lobe numbness).

Neck dissection: CN XI injury (shoulder drop), IJV sacrifice (facial oedema), chyle leak (left level IV/Vb), marginal mandibular nerve injury (lip droop).

Radiotherapy (H&N): mucositis, xerostomia, osteoradionecrosis of mandible, dental caries, trismus, hypothyroidism.

Cisplatin toxicity: nephrotoxicity, ototoxicity, nausea/vomiting, myelosuppression, neuropathy.

Active Recall - Complications of Neck Mass Treatments

References

^[1] Lecture slides: GC 218. I have a swelling in the neck Neck mass (Notes).pdf ^[2] Senior notes: felixlai.md (Salivary gland tumour complications section, parotid surgery) ^[4] Senior notes: felixlai.md (Thyroidectomy complications section, NPC complications) ^[5] Senior notes: maxim.md (Thyroidectomy early/late complications, parathyroid complications, post-op dyspnoea DDx) ^[8] Lecture slides: GC 218. I have a swelling in the neck Neck mass.pdf ^[9] Senior notes: felixlai.md (Oropharyngeal cancer treatment complications) ^[11] Senior notes: felixlai.md (Lymph node dissection complications)