GC218 I Have A Swelling In The Neck Neck Mass
A neck mass is an abnormal lump or swelling in the neck that may arise from enlarged lymph nodes, thyroid pathology, salivary gland disorders, congenital cysts, or neoplastic processes requiring systematic evaluation based on patient age, location, and duration.
Neck Mass — "I Have a Swelling in the Neck"
Lecture Map
A neck mass is one of the most common surgical presentations in head & neck surgery. The clinical challenge is to rapidly categorize the swelling as benign vs. malignant, and if malignant, primary vs. secondary (metastatic). Your approach is driven by age, location, clinical features, and targeted investigations. This lecture by Prof. William I. Wei (ENT/Head & Neck Surgery) provides the framework you need for both clinical practice and the Fourth Summative exam. [1]
- Classify neck masses (benign – congenital/infective; malignant – primary/secondary) [1]
- Systematically diagnose a neck mass using age, growth rate, location, consistency, and special signs [1]
- Localize neck masses (supraclavicular, midline, lateral) and link location to likely pathology [1]
- Select appropriate investigations (FNA, endoscopy, imaging, PET) [1]
- Understand management principles: congenital lesions → surgery; lymph nodes → investigate first, don't just excise; malignant LN → find the primary [1]
- Know when excision LN biopsy is appropriate and how to handle the specimen [1]
- Appreciate follow-up for treated neck masses including "unknown primary" surveillance [1]
Neck mass questions appear repeatedly in Fourth Summative MCQs (matching diagnosis to clinical scenario), minicases (progressive-disclosure format working up a thyroid nodule or cervical lymphadenopathy), and SAQs (differential diagnosis lists, investigations, complications of thyroidectomy). You must be able to generate a structured DDx by location, describe the workup, and discuss management including surgical complications. [3][4][5][6]
Core Concepts and Mechanisms
Neck masses are classified as Benign (Congenital or Infective) or Malignant (Primary or Secondary). [1]
This is the first-principles framework. Every neck mass you encounter should be mentally slotted into one of these four boxes:
| Category | Subcategory | Examples | Why it matters |
|---|---|---|---|
| Benign | Congenital | Thyroglossal cyst, branchial cleft cyst, cystic hygroma, dermoid cyst | Present in young patients; grow slowly; may cause functional disturbance if left untreated |
| Benign | Infective | Reactive lymphadenopathy, TB lymphadenitis, abscess | Tenderness, fever, history of infection; treated medically first |
| Malignant | Primary | Lymphoma, salivary gland malignancy, thyroid carcinoma | Arises de novo in neck structures |
| Malignant | Secondary | Metastatic cervical LN from NPC, laryngeal SCC, GI tract, thyroid | Most common malignant neck mass in adults; finding the primary is critical |
Why this matters from first principles: The neck contains a dense concentration of lymph nodes (draining the entire head and neck region plus receiving lymph from distant sites via the thoracic duct on the left), plus the thyroid gland, salivary glands, embryological remnants, and neurovascular structures. Any of these can produce a mass, and the clinical approach must distinguish between them efficiently.
2. Diagnostic Approach
Diagnosis is based on: Age, Rate of growth, and Clinical features (Location, Consistency/transillumination, Size/mobility/surface/edge, Tenderness/pulsation). [1]
| Age Group | Most Likely Pathology | Rationale |
|---|---|---|
| Children / Young adults | Congenital lesions (thyroglossal cyst, branchial cyst, cystic hygroma) | Embryological remnants manifest during growth |
| Young adults | Inflammatory / reactive LN, lymphoma | Active immune system, infections; lymphoma peaks in young adults |
| Middle-aged / Elderly | Malignant (primary or metastatic) | Cumulative carcinogen exposure; malignancy incidence rises with age |
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. [2]
This is a lecture-notes teaching point that examiners love to test. A rapidly enlarging, painless, hard neck mass in a 60-year-old smoker is malignant until proven otherwise. A slowly growing, painless, soft/cystic midline mass in a 10-year-old is almost certainly congenital.
- Slow growth → benign (congenital cyst gradually expanding, benign tumour like pleomorphic adenoma)
- Rapid growth → malignant, or haemorrhage into a cyst/nodule, or acute infection
- Acute onset (days) → infection/abscess, haemorrhage into thyroid cyst
Location, Consistency/transillumination, Size/mobility/surface/edge, Tenderness/pulsation [1]
| Feature | What it tells you | Examples |
|---|---|---|
| Location | Narrows DDx dramatically (see Location section below) | Midline = thyroid/thyroglossal; lateral = LN/salivary; supraclavicular = metastatic |
| Consistency | Cystic vs solid vs hard vs rubbery | Cystic = cyst; rubbery = lymphoma; hard = carcinoma; fluctuant = abscess |
| Transillumination | Distinguishes cystic from solid | Cystic hygroma transilluminates brilliantly [2]; thyroglossal cyst also transilluminates |
| Size | Larger masses → more likely significant | > 2 cm LN in an adult is suspicious |
| Mobility | Mobile = likely benign; fixed = malignant (infiltration) | Fixed to skin or deep structures suggests malignancy |
| Surface/Edge | Smooth = benign; irregular = malignant | Multinodular = MNG; irregular hard = carcinoma |
| Tenderness | Suggests inflammation/infection | TB LN, acute suppurative LN, thyroiditis |
| Pulsation | Vascular lesion | Carotid body tumour is pulsatile [2] |
Special Examination Manoeuvres for Neck Mass
- Swallowing test: Ask patient to hold water in mouth, then swallow → mass moves up = thyroid origin or thyroglossal cyst (because thyroid is enclosed in pretracheal fascia attached to trachea via Berry's ligament) [7][8]
- Tongue protrusion test (tongue tug test): Mass moves up on tongue protrusion → thyroglossal cyst (because the thyroglossal duct connects foramen cecum of tongue to thyroid, passing through/near hyoid bone) [7][8]
- Pulsatility vs transmitted pulsation: A carotid body tumour has intrinsic pulsation; a mass overlying the carotid artery has transmitted pulsation. Place fingers on either side – if the mass expands outward (expansile pulsation), it is intrinsically vascular.
3. Location-Based Differential Diagnosis
This is the highest-yield clinical framework from this lecture. Examiners will give you a clinical scenario and expect you to generate a DDx based on location.
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. [1]
Why the supraclavicular fossa is special:
- Left supraclavicular node (Virchow's node / Troisier's sign): The thoracic duct drains into the left subclavian vein. Abdominal malignancies (especially gastric, pancreatic, colorectal, ovarian) metastasize via the thoracic duct to the left supraclavicular LN.
- Right supraclavicular node: Drains the mediastinum → lung cancer, esophageal cancer.
- Papillary thyroid carcinoma: Although the primary may be tiny and impalpable, it has a strong propensity for lymphatic spread → may present with cervical LN metastasis as the first sign (so-called "lateral aberrant thyroid" is actually metastatic papillary thyroid CA) [1][7]
| Cause | Mechanism |
|---|---|
| GI tract malignancy (gastric, pancreatic) | Lymphatic drainage via thoracic duct → left Virchow's node |
| Lung/mediastinal malignancy | Direct lymphatic drainage → right supraclavicular |
| Papillary thyroid CA | Lymphatic spread; may have occult primary |
| Lymphoma | Any LN group can be involved |
| TB lymphadenitis | Cervical is the commonest site for TB LN |
Lower neck – lesions from the thyroid gland. Upper neck – thyroglossal cyst. [1]
| Location | Likely Diagnosis | Key Features |
|---|---|---|
| Upper midline (at/above hyoid level) | Thyroglossal cyst | Moves with swallowing AND tongue protrusion; at thyrohyoid membrane level (60%); midline; cystic; may become infected |
| Dermoid cyst | Midline, does NOT move with swallowing or tongue protrusion; subcutaneous; doughy | |
| Ranula | Floor of mouth; cystic; sublingual gland retention cyst | |
| Lower midline | Thyroid pathology | Moves with swallowing only; could be nodule, goitre, or carcinoma |
| Thyroid isthmus nodule | ||
| Pyramidal lobe enlargement (Hashimoto's) |
Thyroglossal Cyst — Key Points [9][7]:
- Failure of thyroglossal tract to obliterate (should happen by gestational weeks 7-10)
- 60% at thyrohyoid membrane level
- Tongue tug test positive (pathognomonic)
- Must confirm normal thyroid gland exists before surgery (USG) — otherwise removing the cyst/tract could render patient hypothyroid
- Sistrunk operation: Remove cyst + entire tract + body of hyoid bone up to foramen cecum → prevents recurrence
- Complications: abscess, fistula, rare papillary CA transformation
Upper neck – salivary gland pathology. Under the cover of sternomastoid muscle – lymph node, inflammatory or neoplastic. Other lesions – branchial cleft cysts, neurofibroma, carotid body tumour etc. [1]
| Sub-location | Likely Diagnosis | Key Features |
|---|---|---|
| Upper lateral (submandibular / parotid region) | Salivary gland pathology | Submandibular gland stone/tumour; parotid tumour (pleomorphic adenoma most common) |
| Under SCM (Level II-IV) | Lymph node | Reactive, TB, metastatic SCC (from NPC, larynx, oropharynx), lymphoma |
| Anterior to SCM (Level II-III) | Branchial cleft cyst | Young adult; cystic; anterior to upper 1/3 SCM; may present after URTI |
| Carotid body tumour (chemodectoma / paraganglioma) | Pulsatile; at carotid bifurcation; mobile side-to-side but NOT up-and-down; may have cranial nerve palsies | |
| Posterior triangle (Level V) | NPC metastatic LN | Bilateral posterior triangle LN → think NPC (especially in Southern Chinese / HK population!) |
| Schwannoma | Slow-growing; firm; attached to nerve | |
| Cystic hygroma | Children; brilliantly transilluminant; soft, compressible |
High Yield: Location-Based DDx Table for Exams
| Location | Midline | Anterior Triangle (Lateral) | Posterior Triangle | Supraclavicular |
|---|---|---|---|---|
| Congenital | Thyroglossal cyst, Dermoid | Branchial cleft cyst, Cystic hygroma | Cystic hygroma | Cervical rib |
| Thyroid | Thyroid nodule/goitre | Thyroid lobe nodule | — | Papillary CA met |
| Salivary | — | Submandibular/parotid mass | — | — |
| LN | Level I (submental) | Level I-IV | Level V (NPC!) | Virchow's node |
| Vascular | — | Carotid body tumour, carotid aneurysm | — | — |
| Neural | — | Neurofibroma, schwannoma | Schwannoma | — |
| Other | Ranula, laryngocele | Laryngocele | — | — |
Understanding lymph node levels helps you predict the primary site of a metastatic neck mass:
| Level | Location | Drains From |
|---|---|---|
| I (IA submental, IB submandibular) | Below mandible | Floor of mouth, anterior tongue, lower lip |
| II (Upper jugular) | Upper 1/3 of IJV, skull base to hyoid | Oral cavity, oropharynx, nasopharynx, parotid |
| III (Middle jugular) | Middle 1/3 of IJV, hyoid to cricoid | Hypopharynx, larynx (supraglottic) |
| IV (Lower jugular) | Lower 1/3 of IJV, cricoid to clavicle | Larynx (subglottic), thyroid, cervical esophagus |
| V (Posterior triangle) | Behind SCM | Nasopharynx (KEY for NPC in HK!), scalp |
| VI (Anterior compartment) | Midline, hyoid to sternum | Thyroid, subglottic larynx |
When the lymph node is rubbery in consistency and occurs in a young patient, lymphoma should be suspected. [2]
Tuberculous infection should be suspected in those patients with poor nutritional status. [2]
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, CT or MRI or angiography; PET. [1]
| Investigation | When to Use | What It Tells You |
|---|---|---|
| Fine Needle Aspiration Cytology (FNAC) | First-line for most neck masses | Differentiates benign/malignant; identifies cell type; low morbidity [2] |
| Endoscopic examination | Suspected metastatic LN (to find primary) | Nasopharyngoscopy, laryngoscopy, pharyngoscopy → biopsy suspicious areas |
| CT scan | Define extent, retrosternal extension, bony invasion | Good for bony detail; fast; contrast-enhanced for LN characterization |
| MRI | Soft tissue detail, parapharyngeal space tumours, perineural spread | Better soft tissue contrast than CT; no radiation |
| Angiography / MRA | Carotid body tumour suspected [2] | Shows vascular supply; "lyre sign" (splaying of ICA/ECA); plan embolization |
| PET scan | Unknown primary with metastatic LN; staging | Identifies metabolically active primary; whole-body staging |
| Ultrasound | Thyroid nodules, superficial LN, guide FNA | Characterize thyroid nodules (TI-RADS); assess LN morphology |
| Thyroid function tests | Any thyroid-related mass | Rule out hyper/hypothyroidism |
Right tonsillectomy & frozen section; Left tonsillectomy; Pharyngoscopy biopsy of hypopharynx & tongue base; Nasopharyngoscopy & biopsy [1]
Why this is done: When a patient presents with a metastatic cervical LN (typically SCC) and the primary site is not found on clinical exam or imaging, a panendoscopy + directed biopsies is performed under general anesthesia. This includes:
- Bilateral tonsillectomy (not just biopsy — because tonsillar SCC can be occult and deep; frozen section done to check intra-operatively)
- Pharyngoscopy with biopsy of hypopharynx and tongue base (common sites of occult primary)
- Nasopharyngoscopy with biopsy (essential in HK/Southern Chinese population due to high NPC incidence)
Why Not Just Biopsy the Neck Node?
Lymph node should be investigated rather than excised. [1] For malignant LNs all efforts should be spent to find the primary tumour. [1]
This is a critical exam point and a common student error. Excising a metastatic LN without finding the primary:
- Disrupts tissue planes → makes subsequent definitive surgery more difficult
- Risks tumour seeding in the wound
- May upstage the disease
- The primary tumour remains untreated and will progress
Always attempt to find the primary FIRST with FNA + endoscopy + imaging before resorting to excision biopsy.
Treatment Principles
Treatment depends on the nature of the mass. [1]
| Pathology | Management | Key Points |
|---|---|---|
| Congenital lesion | Surgical removal at appropriate age [1] | Their increase in size may cause functional disturbances (airway compression, cosmetic, infection) |
| Thyroglossal cyst | Sistrunk operation (cyst + tract + hyoid body) | Must confirm normal thyroid exists first [9] |
| Branchial cleft cyst | Surgical excision | Risk of recurrence if incompletely excised |
| Cystic hygroma | Surgical excision; may use sclerotherapy | Can be very extensive; risk of recurrence |
| Infection-related LN | Treated with antibiotics [1] | May need drainage if abscess forms |
| TB LN | Anti-TB chemotherapy [1] | NOT primarily surgical; 6-9 months Rx; may form cold abscess/sinus |
| Lymphoma suspected | Excision LN biopsy → send as fresh specimen [1] | Need architecture for classification; FNA alone insufficient for lymphoma diagnosis |
| Metastatic LN (known primary) | Treat the primary + neck dissection ± RT/chemo | Comprehensive treatment plan |
| Metastatic LN (unknown primary) | Find primary (panendoscopy + PET) → treat accordingly | Regular follow-up essential even after treatment [1] |
Done as last resort. When lymphoma is suspected the excised LN should be sent as fresh specimen. [1]
Why fresh specimen for lymphoma?
- Lymphoma diagnosis requires assessment of tissue architecture (distinguishing Hodgkin's from non-Hodgkin's, determining subtype)
- Formalin fixation destroys some markers needed for immunohistochemistry and flow cytometry
- Fresh tissue allows: flow cytometry, cytogenetics, molecular studies
- FNA alone cannot reliably diagnose or subtype lymphoma
Infection related LN – treated with antibiotics. TB LN – treated with anti-TB chemotherapy. [1]
Why not excise TB LN? Because:
- TB is a systemic disease → needs systemic treatment
- Excision of TB LN can lead to chronic draining sinus
- Anti-TB chemotherapy is curative
- Surgery reserved for diagnostic biopsy if FNA is inconclusive
Recurrence of the pathologies treated, both benign and malignant. LN treated for unknown primary, the patient should be followed up regularly. [1]
Why regular follow-up for unknown primary?
- The primary tumour may declare itself months to years later
- Patient is at risk of developing a new primary (field cancerization in smokers/drinkers → multiple aerodigestive tract primaries)
- Recurrence in the neck is possible
- Late effects of treatment (radiation, chemotherapy) need monitoring
Specific Conditions — Detailed Notes
Since thyroid pathology is the most common cause of a midline neck mass and is heavily tested, here are the key points integrating GC 218 with GC 177 (thyroid nodules) and the Case 2 study guide:
Key clinical features suggesting malignancy in a thyroid nodule [7][10]:
- Hard consistency
- Fixed/immobile
- Rapid growth
- Hoarseness (recurrent laryngeal nerve invasion)
- Cervical lymphadenopathy
- Dysphagia/dyspnoea (invasion/compression)
- Family history of thyroid cancer or MEN syndrome
- History of neck irradiation
- Male sex (thyroid nodules are commoner in females, but nodules in males have higher malignancy rate)
- Extremes of age ( < 20 or > 60)
Investigation of a thyroid nodule:
- TFTs (is the patient hyper/hypo/euthyroid?)
- Ultrasound (characterize the nodule — solid/cystic, microcalcifications, irregular margins, taller-than-wide, increased vascularity)
- FNAC (most important test — Bethesda classification)
- Thyroid scan (if thyrotoxic — hot nodule = toxic adenoma; cold nodule = higher malignancy risk)
- CT/MRI (if retrosternal extension, assess extent, tracheal deviation)
Pre-operative assessment before thyroidectomy [11][12]:
- Flow-volume loop (if concern about airway obstruction)
- CT/MRI for extent
- Flexible laryngoscopy to document pre-operative vocal cord function (medicolegal importance!)
- If thyrotoxic: achieve euthyroid state first with carbimazole → propranolol → Lugol's iodine
Complications of thyroidectomy (very high yield!) [11][12]:
| Timing | Complication | Mechanism/Details |
|---|---|---|
| Immediate | Haematoma (0.1-1.25%) | Paratracheal → venous obstruction → acute laryngeal oedema → airway compromise. Emergency: cut sutures at bedside, evacuate clot |
| Seroma | Superficial, mobile; self-limiting | |
| Early | RLN injury → vocal cord paralysis (< 1%) | Unilateral: hoarseness → medialization thyroplasty. Bilateral: stridor/dyspnoea upon extubation → re-intubation ± tracheostomy |
| SLN injury | Weak voice, cannot sing high pitch | |
| Thyroid storm | Release of stored hormone; more risk if not rendered euthyroid pre-op | |
| Tracheomalacia | Cartilage degeneration after removal of long-standing compressive goitre | |
| Intermediate | Hypocalcaemia / Hypoparathyroidism | 10-20% transient, 1-4% permanent. Due to parathyroid gland removal or devascularization. Symptoms: perioral/digital paraesthesia, tetany (Trousseau's, Chvostek's signs), laryngospasm, seizures. Treat: IV calcium gluconate → oral calcium + vitamin D |
| Late | Hypothyroidism | Expected after total thyroidectomy → lifelong levothyroxine replacement |
| Recurrence of disease | ||
| Keloid/scar | Kocher incision |
Emergency: Post-Thyroidectomy Neck Haematoma
A tense, expanding neck swelling after thyroidectomy with respiratory distress is a surgical emergency. Do NOT wait for imaging or senior review before acting:
- Open the wound at bedside — cut skin sutures and strap muscle sutures
- Evacuate the haematoma
- Call for senior help and anaesthetist for re-intubation
- Return to OR for definitive haemostasis
Delay = death from airway obstruction.
- Arises from chemoreceptor cells at carotid bifurcation
- Pulsatile [2], expansile
- Fontaine's sign: Mobile side-to-side but NOT craniocaudally (tethered to carotid bifurcation)
- Imaging: "Lyre sign" on angiography (splaying of ICA and ECA)
- May be bilateral (especially familial cases)
- Pre-operative embolization may reduce bleeding
- Treatment: surgical excision (risk of stroke, cranial nerve injury)
- From incomplete obliteration of 2nd branchial cleft (most common)
- Presents in young adults (late teens to 30s)
- Location: anterior border of upper 1/3 SCM, at junction of upper and middle 1/3
- Fluctuant, non-tender, smooth
- May enlarge after URTI (lymphoid tissue in wall responds to infection)
- Treatment: surgical excision
- Important caveat: In a patient > 40 with a "cystic" lateral neck mass → think cystic metastasis from SCC (especially tonsillar/HPV-related oropharyngeal SCC), NOT branchial cyst
- Congenital lymphatic malformation
- Most common in posterior triangle, children
- Transilluminates brilliantly [2]
- Soft, compressible, may be massive
- Can extend into mediastinum or floor of mouth
- Treatment: surgical excision (may be difficult due to infiltrative nature); sclerotherapy (OK agent, bleomycin)
From GC 218 context and 2024 SAQ Q3 [6]:
- Ludwig's angina: bilateral submandibular space infection → swollen floor of mouth → airway emergency
- Most common origin: odontogenic (dental infection)
- If crepitus present → necrotizing fasciitis (gas-forming infection)
- Investigation: CT neck with contrast (confirms abscess vs cellulitis, extent)
- Management: IV antibiotics, airway management, surgical drainage (incision & drainage), consider tracheostomy if airway threatened
Exam Intelligence
| Trap | Why Students Get It Wrong | Correct Approach |
|---|---|---|
| Midline mass that moves with swallowing → calling it thyroglossal cyst | Must also check tongue protrusion. Thyroid masses also move with swallowing. Thyroglossal cyst moves with BOTH swallowing and tongue protrusion. | If only moves with swallowing → thyroid. If moves with tongue protrusion too → thyroglossal. |
| Excising a cervical LN as first step | Tempting to "just take it out and send it". But this disrupts planes and may worsen staging. | FNA first → endoscopy → imaging → excision biopsy only as last resort |
| "Branchial cyst" in a 60-year-old | Branchial cysts present in young adults. A cystic lateral neck mass in an older patient is likely cystic metastasis (SCC) until proven otherwise. | Age changes your DDx! |
| Not sending lymphoma specimen fresh | Formalin ruins flow cytometry and some IHC markers | Always specify "fresh specimen" when lymphoma is suspected |
| Forgetting to check for normal thyroid before Sistrunk operation | If the only functioning thyroid tissue is ectopic (along the thyroglossal tract), removing it causes hypothyroidism | USG to confirm normal thyroid in situ |
| Post-thyroidectomy hoarseness = RLN injury | Could also be SLN injury (cannot sing high pitch but otherwise OK) or intubation trauma | Describe specific voice changes; pre-op laryngoscopy is medicolegal standard |
| Diffuse goitre + tachycardia + tremor in young woman → Thyroid cancer | This is Graves' disease! Diffuse = not nodular; tachycardia + tremor = thyrotoxicosis. Cancer typically presents as a nodule, not diffuse goitre. | Graves' = diffuse goitre + thyrotoxicosis + eye signs |
| Scenario | Answer | Why NOT the others |
|---|---|---|
| 2 cm upper midline neck mass, tongue tug test positive | Thyroglossal cyst | Not thyroid (tongue tug negative); not dermoid (doesn't move with swallowing or tongue) |
| Diffuse central neck swelling + tachycardia + proptosis + irregular pulse | Graves' disease | Not MNG (diffuse, not multinodular); not thyroid cancer (no nodule); AF from thyrotoxicosis |
| 3 cm right neck hard mass + moves with swallowing + cervical LN + paroxysmal headache/palpitation/sweating + raised CEA + calcitonin | Medullary thyroid carcinoma | Calcitonin is produced by parafollicular C cells → pathognomonic for MTC. Paroxysmal symptoms suggest associated phaeochromocytoma (MEN 2) |
| Acute onset 4 cm left thyroid swelling in 2 days, preceded by coughing | Thyroid haemorrhagic cyst | Acute onset = haemorrhage into pre-existing cyst; thyroiditis is painful + systemic; cancer doesn't enlarge in 2 days |
| Small goitre + raised TSH + raised anti-TPO | Hashimoto thyroiditis | Raised TSH = hypothyroid; anti-TPO = autoimmune; not Graves (which has LOW TSH) |
| 30-year-old woman, right upper neck mass, slowly growing for 3 years, no other symptoms | Pleomorphic adenoma (of parotid/submandibular gland) | Slow growth over years + young woman + upper neck + no other symptoms = classic benign salivary tumour |
| 65-year-old man, chronic smoker/drinker, hoarseness + right neck mass + haemoptysis | Squamous cell carcinoma (of larynx with cervical metastasis) | Smoking + alcohol + hoarseness = laryngeal SCC; neck mass = metastatic LN; haemoptysis from laryngeal tumour |
| 40-year-old lady, central neck mass that moves with swallowing | Papillary thyroid carcinoma (most common thyroid cancer) | In 2025 MCQ context [5]; not thyroglossal (tongue tug not mentioned); age + solitary nodule + moves with swallowing = thyroid origin |
Past Paper Questions
Section 1 (20 marks):
"Mrs. Chan is a 40-year-old lady attending your clinic and has been complaining of a neck swelling. Name five tissues/organs and one differential diagnosis within each tissue/organ for the neck swelling."
Model answer:
| Tissue/Organ | Differential Diagnosis |
|---|---|
| Thyroid gland | Multinodular goitre / thyroid nodule / thyroid carcinoma |
| Lymph node | Reactive lymphadenopathy / metastatic LN / lymphoma / TB LN |
| Salivary gland (submandibular/parotid) | Pleomorphic adenoma / salivary gland stone |
| Congenital/embryological remnant | Thyroglossal cyst / branchial cleft cyst / cystic hygroma |
| Blood vessel | Carotid body tumour / carotid artery aneurysm |
Other acceptable: Skin/subcutaneous (lipoma, sebaceous cyst, dermoid), muscle/soft tissue (sternomastoid tumour in infant), nerve (schwannoma, neurofibroma)
Section 2 (28 marks):
"The swelling moved with swallowing... What is the most likely origin? List four possible pathologies."
Answer: Most likely origin = Thyroid gland (moves with swallowing). Four pathologies: (1) Multinodular goitre, (2) Thyroid adenoma, (3) Thyroid carcinoma, (4) Thyroid cyst.
"List four clinical signs that may suggest a malignant cause."
Answer: (1) Hard consistency, (2) Fixed/tethered to surrounding structures, (3) Cervical lymphadenopathy, (4) Hoarseness of voice (RLN involvement). Others: rapid growth, irregular surface.
Section 3-4: Progressive disclosure revealing thyrotoxicosis features (palpitations, tremor, weight loss, tachycardia 130 bpm) with a left thyroid nodule. Blood tests show suppressed TSH, elevated T4. USG shows hypoechoic nodule; FNA shows hyperplastic nodule; thyroid scan shows increased uptake in left lower pole. This is consistent with a toxic adenoma (autonomous functioning thyroid nodule).
"A 20-year-old woman presented with central neck swelling for 6 months. On examination, there was a diffuse swelling at the central neck that moved with swallowing. She was also found to have tachycardia and resting tremor upon examination of the hands. What is the MOST LIKELY diagnosis?" A. Follicular carcinoma of the thyroid B. Grave disease ✓ C. Thyroglossal cyst D. Thyroid cyst
Rationale: Diffuse central swelling (not nodular) + moves with swallowing (thyroid origin) + tachycardia + tremor (thyrotoxicosis symptoms) = classic Graves' disease. Not thyroglossal cyst (diffuse, not discrete; no tongue tug test mentioned). Not follicular carcinoma (presents as nodule, usually euthyroid). Not thyroid cyst (doesn't cause tachycardia/tremor).
"A 65-year-old man, who is a chronic smoker and chronic drinker, presents with hoarseness, a right neck mass and infrequent haemoptysis for 2 months."
Answer: J. Squamous cell carcinoma. Rationale: Chronic smoker + drinker (classical risk factors for head & neck SCC) + hoarseness (laryngeal primary) + neck mass (metastatic LN) + haemoptysis = laryngeal SCC with cervical metastasis.
"A 30-year-old woman has a right upper neck mass for 3 years. It slowly increases in size without any other symptoms."
Answer: I. Pleomorphic adenoma. Rationale: Young woman + upper neck (parotid/submandibular region) + slowly growing over 3 years + no other symptoms = classic pleomorphic adenoma (most common salivary gland tumour, benign but slowly enlarging).
"80-year-old lady, enlarging neck swelling, increasing difficulty breathing for 6 months. Multinodular swelling at anterior lower neck, moves with swallowing. Cannot get below the mass on the right. Trachea deviated to the left."
Key answers:
- Organ: Thyroid gland
- Physical signs of significant mass effect: (1) Cannot get below the mass = retrosternal extension, (2) Tracheal deviation
- Investigations: (1) TFTs, (2) USG thyroid + FNAC, (3) CT neck/thorax (retrosternal extension), (4) Flexible laryngoscopy (vocal cord function)
- Benign diagnosis: Multinodular goitre
Section 4 asks about post-total-thyroidectomy care → monitor for haematoma, RLN injury (voice), hypocalcaemia (check serum calcium, Trousseau's/Chvostek's signs).
Q4: "2 cm upper neck mass at midline, tongue tug test positive" → H. Thyroglossal cyst Q5: "Diffuse goitre, proptosis, irregular pulse" → B. Graves disease Q6: "3 cm right neck hard mass moves with swallowing, multiple enlarged right lateral neck LN, paroxysmal headache/palpitation/sweating, raised CEA and calcitonin" → D. Medullary thyroid carcinoma Q7: "Acute onset 4 cm left thyroid swelling in 2 days, preceded by bouts of coughing" → J. Thyroid haemorrhagic cyst Q8: "Small goitre, raised TSH and anti-TPO antibodies" → C. Hashimoto thyroiditis
"An 18-year-old lady presented with central neck swelling for 6 months. She also feels hot easily and her menstrual cycle was disturbed. On examination, the central neck was diffusely enlarged and the swelling moved with swallowing. What is the MOST LIKELY diagnosis?" A. Cervical lymphadenopathy B. Lipoma C. Thyroid nodule hyperplasia ✓ D. Warthin tumour
Rationale: Central + diffuse + moves with swallowing = thyroid. Feels hot + menstrual disturbance = thyrotoxicosis. "Thyroid nodule hyperplasia" in this context likely refers to a hyperplastic/nodular thyroid (could be Graves' or toxic MNG). Not cervical LN (doesn't move with swallowing). Not lipoma (doesn't move with swallowing, not associated with thyrotoxicosis). Not Warthin tumour (salivary gland tumour, posterior tail of parotid).
"65-year-old gentleman, 4-day history of sore throat and painful neck swelling. Fever 39°C, swollen floor of mouth and right painful neck swelling." (a) Most likely diagnosis: Ludwig's angina / Deep neck space infection (b) Most common infective origin: Odontogenic (dental infection) (c) Investigation: CT neck with contrast (d) Crepitus of right neck → Necrotizing fasciitis (e) Management: IV antibiotics, surgical drainage (I&D), airway management/protection (may need tracheostomy), fluid resuscitation
"40-year-old woman, acute onset 3 cm right thyroid swelling within 2 days. Tracheal deviation to left. Some difficulty swallowing." (a) Three DDx: (1) Haemorrhage into thyroid cyst, (2) Thyroiditis (subacute/De Quervain's), (3) Rapidly enlarging thyroid carcinoma (e.g., anaplastic — rare at age 40) (b) Investigations: USG thyroid, FNAC (c) Treatment: Aspiration of cyst / observation / surgery (thyroid lobectomy) depending on pathology (d) Complication: RLN injury (hoarseness) / hypocalcaemia / haematoma
Q22: "60-year-old man, right upper neck mass, growing for 5 years, no other symptoms" → G. Pleomorphic adenoma Q23: "50-year-old man, newly diagnosed NPC. FNA to right level V mass" → J. Undifferentiated carcinoma (NPC in HK is predominantly undifferentiated/non-keratinizing type, WHO Type III) Q24: "40-year-old lady, central neck mass that moves with swallowing" → F. Papillary thyroid carcinoma (most common thyroid malignancy; age 40 + solitary central mass) Q25: "90-year-old lady, fungating breast mass on palliative treatment, multiple lower neck masses. FNA to mass" → B. Invasive ductal carcinoma (metastatic breast cancer to supraclavicular LN)
Integration with Related Lectures
- Bethesda classification for FNAC
- TI-RADS scoring on USG
- Indications for thyroidectomy (malignancy, compressive symptoms, retrosternal extension, cosmetic)
- Thyroid cancer types: Papillary (most common, best prognosis, lymphatic spread) > Follicular (haematogenous spread) > Medullary (C cells, calcitonin, MEN2) > Anaplastic (worst prognosis, elderly)
- Pleomorphic adenoma: most common salivary tumour; slow growth; risk of malignant transformation if left for decades
- Warthin's tumour: 2nd most common parotid tumour; bilateral in 10%; associated with smoking
- Mucoepidermoid carcinoma: most common salivary malignancy
- Adenoid cystic carcinoma: perineural invasion; slow but relentless growth; late distant metastasis
- Southern Chinese/HK: very high incidence
- Presents with neck mass (posterior triangle LN!) in 40% as first symptom
- EBV associated; serology (anti-VCA IgA, anti-EA IgA) for screening
- Undifferentiated carcinoma (WHO Type III) most common in HK
- Treatment: concurrent chemoradiotherapy (NOT surgery for primary)
- Oropharyngeal SCC (HPV-related): may present with cystic cervical LN metastasis
- Oral cavity SCC: risk factors = smoking, alcohol, betel nut
- Floor of mouth and lateral tongue are common sites
- Large goitre can cause upper airway obstruction
- Tracheostomy may be needed emergently if bilateral RLN palsy post-thyroidectomy
Diagnosis: age, location & clinical features. Investigation: imaging, FNA, excision. Treatment: nature of pathology. [1]
High Yield Summary
- Classify neck masses as Benign (Congenital/Infective) or Malignant (Primary/Secondary).
- Age is the single most important initial clue: young = congenital, old = malignant.
- Location determines DDx: Midline upper = thyroglossal cyst; Midline lower = thyroid; Lateral upper = salivary; Under SCM = lymph node; Supraclavicular = metastatic (GI/lung/thyroid).
- Clinical features: Consistency (hard = malignant, rubbery = lymphoma, cystic = cyst); Mobility (fixed = malignant); Transillumination (brilliant = cystic hygroma); Pulsation (carotid body tumour).
- Swallowing test: mass moves up = thyroid or thyroglossal. Tongue protrusion test: mass moves up = thyroglossal only.
- FNA is first-line investigation for most neck masses. Endoscopy of upper aerodigestive tract is essential for suspected metastatic LN.
- Never excise a cervical LN as first step without investigating — find the primary first. Excision biopsy is the last resort, reserved for suspected lymphoma (send FRESH).
- Congenital lesions: remove surgically. Infective LN: antibiotics/anti-TB. Malignant LN: find and treat primary + neck dissection.
- Post-thyroidectomy emergencies: Haematoma (open sutures at bedside!), Bilateral RLN palsy (stridor → re-intubation), Hypocalcaemia (IV calcium gluconate).
- Follow-up is mandatory, especially for unknown primary — the primary may declare itself later.
Active Recall - Neck Mass
[1] Lecture slides: GC 218. I have a swelling in the neck Neck mass.pdf [2] Lecture notes: GC 218. I have a swelling in the neck Neck mass (Notes).pdf [3] Past papers: 2019 Fourth Summative Mini Case.pdf (Case Two, Sections 1-4) [4] Past papers: 2020 Fourth Summative Assessment MCQ paper.pdf (Q58) [5] Past papers: 2022 Fourth Summative MCQ.pdf (Q11-15); 2023 Fourth Summative MCQ.pdf (Q4-8); 2025 Fourth Summative MCQ.pdf (Q21-25); 2022 Fourth Summative Minicase.pdf (Case Two) [6] Past papers: 2024 Fourth Summative MCQ.pdf (Q59); 2024 Fourth Summative SAQ.pdf (Q3, Q9) [7] Senior notes: MBBS Final MB (Surgery) (Felix PY Lai).pdf (pp. 121, 1002-1004) [8] Senior notes: MBBS Final MB (Medicine) (Felix PY Lai).pdf (p. 1595-1597) [9] Senior notes: Maksim Surgery Notes.pdf (p. 193-194) [10] Lecture slides: GC 177. A thyroid nodule benign thyroid nodules; thyroid cancer.pdf [11] Senior notes: Ryan Ho Endocrine.pdf (pp. 7, 17, 22) [12] Senior notes: Endocrine Interactive Tutorial.pdf (pp. 1, 3-4) [13] Lecture slides: GC 217. Facial nerve palsy and salivary gland diseases.pdf [14] Lecture slides: GC 215. Common nasal conditions and nasopharyngeal carcinoma.pdf [15] Lecture slides: GC 219. Infections and tumours in pharynx and oral cavity.pdf [16] Lecture slides: GC 220. Upper airway obstruction and tracheostomy.pdf
GC217 Facial Nerve Palsy And Salivary Gland Diseases
Facial nerve palsy is the loss of voluntary facial muscle movement due to dysfunction of cranial nerve VII, and salivary gland diseases encompass inflammatory, obstructive, and neoplastic conditions affecting the parotid, submandibular, and sublingual glands, often clinically linked because parotid pathology can compromise the facial nerve.
GC218 I Have A Swelling In The Neck Neck Mass (notes)
A neck mass is an abnormal lump or swelling in the neck that may arise from congenital, inflammatory/infectious, or neoplastic causes involving structures such as lymph nodes, thyroid, salivary glands, or developmental remnants.