Nipple Discharge Or Inversion

• Normal milk production during pregnancy, postpartum and for up to 6 months to 2 years after cessation of breastfeeding.
• Bloody nipple discharge can occur in ~20% of women during the 2nd or 3rd trimester and during lactation — this is usually benign (caused by rapidly proliferating ductal epithelium and increased vascularity) ^[2].

"Galactorrhoea" → from Greek: gala = milk, rhoia = flow.

• Typically bilateral, involving multiple ducts, and milky in appearance.
• The underlying mechanism is almost always hyperprolactinaemia — prolactin is the key hormone driving milk synthesis by mammary alveolar epithelial cells.

Why does prolactin go up?

Normally, prolactin secretion from anterior pituitary lactotroph cells is under tonic inhibitory control by dopamine from the hypothalamus (via the tuberoinfundibular pathway). Anything that:

1. Produces prolactin autonomously (prolactinoma),
2. Blocks dopamine (drugs), or
3. Interrupts the dopamine pathway (stalk compression, infiltrative disease) → removes tonic inhibition → prolactin rises → galactorrhoea.

This is the category that surgeons worry about. The hallmarks of pathological discharge are:

• Spontaneous (comes out without squeezing)
• Persistent
• Unilateral
• Single-duct
• Serous (clear/yellow), sanguineous (bloody), or serosanguineous (blood-tinged)

Key slide point: History must determine — unilateral or bilateral, blood-stained/milky/serous, spontaneous or on manual expression; on examination — single duct or multiple duct, nature/colour of discharge, any palpable breast mass or axillary lymph node ^[1].

• Usually bilateral and benign.
• Results from failure of the underlying mesenchymal tissue to proliferate and project the nipple papilla outwards during development ^[2].
• Very common (~10–20% of women). The nipple can often be manually everted.
• No association with malignancy.

Acquired = new-onset in someone who previously had a normal, everted nipple. This is the clinically worrying scenario.

• Hands on hips / press inward → contracts pectoralis major → accentuates skin dimpling/tethering and fixation to muscle.
• Arms overhead → stretches skin → reveals subtle skin changes and asymmetry.
• Lean forward → breasts hang freely → any mass fixed to the chest wall will not swing with the breast.

"Mammography" → from Latin mamma = breast + Greek graphein = to write/record. It is a low-dose X-ray of the breast.

Mammogram: only for female > 35 years (poor resolution in dense breasts in young females) ^[3]

Why age > 35? Younger women have dense fibroglandular tissue that appears white on mammography — the same colour as tumours. This "white-on-white" problem makes mammography insensitive in young dense breasts. After age 35, breast tissue gradually involutes and is replaced by radiolucent fat, making masses and calcifications much more conspicuous.

Standard views ^[2][3]:

• Craniocaudal (CC) view: X-ray beam goes from top to bottom. Shows medial-to-lateral extent. Used to determine inner vs outer quadrant.
• Mediolateral oblique (MLO) view: X-ray beam at 45° angle. Shows the axillary tail, axillary lymph nodes, and upper outer quadrant in detail ^[2]. Used to determine upper vs lower half (line perpendicular to pectoralis major).

Mammographic features of malignancy ^[2][3]:

Mammography for nipple discharge specifically:

• Look for microcalcifications (DCIS)
• Look for a retroareolar mass (papilloma, carcinoma)
• Look for dilated calcified ducts (duct ectasia) ^[4]
• In Paget's disease: mammography is mandatory to look for associated mass and exclude synchronous cancers or widespread calcification ^[2]

Limitations of mammography ^[2]:

• Cannot make a definitive diagnosis — can only depict a mass as abnormal or suspicious
• Dense breast tissue can obscure lesions
• Cannot reliably distinguish benign from malignant without biopsy

USG breast: for all patients ^[3]

Why USG for everyone? Because it complements mammography perfectly — it works best precisely where mammography is weakest (dense breasts, young women, cystic vs solid differentiation).

Roles of USG ^[2][3]:

• Improved sensitivity and specificity combined with mammogram, especially in young women with dense breast tissue ^[3]
• Distinguish cysts from solid lesions ^[3] — this is crucial because a simple cyst needs no further intervention
• Guide FNAC, biopsy, and clipping before neoadjuvant chemotherapy ^[3]
• Assess axillary lymph nodes ^[3] — suspicious LN: loss of fatty hilum ^[3]
• First imaging study in young women ( < 35) or women who are pregnant or lactating ^[2]
• Identify presence of a prominent vascular supply (colour Doppler)

USG features — benign vs malignant ^[2]:

Mnemonic for suspicious USG features: "SHIT CME" — same features as suspicious thyroid nodules ^[3]: Solid, Hypoechoic, Irregular margins, Taller-than-wide, Calcification (micro), Microlobulation, Extra-thyroidal extension (in breast: chest wall invasion)

USG for nipple discharge specifically:

• Look for a dilated duct with intraluminal mass (papilloma)
• Look for a retroareolar abscess cavity (periductal mastitis/abscess)
• Look for a solid retroareolar mass (carcinoma)
• Characterise any cyst: simple (anechoic, posterior enhancement) vs complex (internal echoes, septations, solid component)

Limitations ^[3]:

• NOT useful as screening — operator-dependent
• Cannot pick up most calcifications ^[3] — mammography is far superior for detecting microcalcifications (DCIS)

The Breast Imaging Reporting and Data System (BI-RADS) is a standardised scoring system applicable to both mammographic and ultrasound findings ^[2]. It translates imaging findings into a management recommendation:

"Ductography" → ductus = duct + graphein = to write/record. It is a contrast study of the lactiferous duct system.

• Technique: A fine cannula is inserted into the discharging duct orifice on the nipple, and water-soluble contrast is injected. Mammographic images are then taken to outline the duct anatomy.
• Purpose: Localise an intraductal lesion (papilloma, DCIS) before surgical duct excision (microdochectomy) ^[2][3].
• Findings:
  • Filling defect = intraluminal mass (papilloma or carcinoma)
  • Duct irregularity or cut-off = possible malignancy
  • Duct ectasia = dilated ducts without filling defects
• Limitations: Invasive, uncomfortable, technically difficult if duct cannot be cannulated, largely being replaced by breast MRI and ductoscopy.

• Technique: A microendoscope (0.5–1.2 mm diameter) is inserted into the discharging duct to directly visualise the duct lumen.
• Purpose: Direct visualisation of intraductal pathology (papilloma, DCIS); can take biopsies under direct vision; helps guide microdochectomy ^[2].
• Advantage: Combines diagnosis and surgical planning in one procedure.
• Limitation: Not widely available; technically challenging; limited to larger ducts.

• When? Not routine for nipple discharge, but useful in specific scenarios:
  • Occult lesion (mammogram and USG negative but clinical suspicion high)
  • Assessment of extent of disease in known malignancy (multifocal/multicentric disease)
  • Screening high-risk patients (BRCA carriers)
  • Evaluation of response to neoadjuvant chemotherapy
• Advantage: Highest sensitivity (~95–100%) for invasive breast cancer; not limited by breast density.
• Limitation: Low specificity (many false positives → unnecessary biopsies); expensive; requires IV gadolinium; not good for calcifications.

• Technique: A fine needle (21–23 gauge) is inserted into the lesion (palpable or USG-guided) and cells are aspirated for cytological examination.
• Advantage: no need for local anaesthesia, smaller needle ^[3]
• Disadvantage: cannot assess architecture (i.e. cannot distinguish carcinoma in-situ from invasive carcinoma) ^[3] — Why? Because FNAC harvests individual cells, not tissue with preserved structure. You cannot tell whether cells have breached the basement membrane.
• Preferred if low risk (e.g. non-palpable mass, equivocal mammogram) or simple cysts ^[3]

FNAC approach to cystic lesions ^[3]:

• Lump disappears / clear fluid obtained → no further investigation
• Residual thickening / blood-stained fluid → core biopsy ^[3]

FNAC approach to solid lesions ^[3]:

• Benign cytology → observe or excision
• Atypical cytology → core needle biopsy (upgrade to histology)
• Malignant cytology → treat as cancer ^[3]

FNAC of nipple discharge (discharge cytology):

• Collect the discharge and send for cytology
• Can identify malignant cells, papillary fragments, inflammatory cells, or foamy macrophages (duct ectasia)
• Low sensitivity — a negative cytology does NOT exclude malignancy
• Useful as an adjunct, not a standalone investigation ^[3]

• Technique: A larger needle (9–14 gauge) with a spring-loaded cutting mechanism obtains a core of tissue, preserving architecture.
• Performed if BI-RADS ≥ 4 ^[3]
• Advantages: architectural assessment, tumour grading, receptor status (ER/PR/HER2) ^[3] — Why better than FNAC? Because a tissue core preserves the relationship between cells and basement membrane, allowing you to determine invasion vs in-situ, grade the tumour, and perform immunohistochemistry.
• Disadvantages: requires local anaesthesia, larger needle (9–14G) ^[3]
• For non-palpable masses: USG-guided, stereotactic (mammographic-guided), tomosynthesis (3D mammogram), or MRI-guided ^[3]
• Increased yield: vacuum-assisted core biopsy (VAB) — uses suction to obtain larger, more representative tissue samples ^[3]

Core biopsy for nipple discharge:

• If imaging identifies a mass lesion (papilloma, suspicious lesion) → USG-guided core biopsy
• If imaging shows microcalcifications without a mass → stereotactic (mammographic-guided) core biopsy

Core biopsy for nipple inversion:

• If a retroareolar mass is identified → USG-guided core biopsy
• If Paget's disease is suspected → full-thickness wedge biopsy of the nipple and underlying breast tissue ^[2]

• When? When core biopsy reveals a suspicious lesion that is not diagnostic, or when there is discordance between clinical/radiological and pathological findings ^[3].
• If atypical hyperplasia (ADH/ALH) is found on core biopsy → excisional biopsy MUST be performed to rule out adjacent malignancy ^[3][6] — Why? Because ADH/ALH on core biopsy is upgraded to DCIS or invasive cancer in ~15–30% of cases when the entire lesion is excised. The core only samples a small part of the lesion.

Localisation of non-palpable lesions for excisional biopsy ^[3]:

• Hook-wire localisation (HWL): a wire with a hook is inserted under imaging guidance to mark the lesion; surgeon excises tissue around the wire tip
  • Problems: extensive normal tissue removal, wire outside skin, risk of broken wire ^[3]
• Radioactive seed localisation (RSL): ¹²⁵I-labelled titanium seed inserted 0–5 days prior to surgery ^[3]
• Radio-opaque lesion localisation (ROLL): ⁹⁹ᵐTc-labelled albumin-based colloid injected within 24 hours of surgery ^[3]
• Magseed localisation: non-radioactive magnetic seed ^[3]
• On-table USG: real-time ultrasound guidance during surgery ^[3]

• Transsphenoidal resection ^[2]
  • Indication 1: Refractory to dopamine agonists — prolactin does not normalise or tumour does not shrink ^[2]
  • Indication 2: Women with giant lactotroph adenoma who wish to become pregnant — Why? If the patient becomes pregnant and discontinues the dopamine agonist during pregnancy (as is often recommended), a giant adenoma may enlarge to clinically significant size before delivery, causing mass effects (visual field defects, headaches) ^[2]
  • The approach is "trans-sphenoidal" = through the sphenoid sinus, which sits just below the pituitary fossa — minimally invasive, avoids craniotomy

• "Micro" = small, "docho" = duct (from Greek dochos), "ectomy" = excision. Literally: excision of a single small duct.
• What it involves: Excision of the single affected lactiferous duct and its associated lobules ^[2]
• Why it is the standard: It is both diagnostic (the entire duct is sent for histology, excluding DCIS or IDC that may be lurking behind the papilloma) and therapeutic (removes the source of discharge)
• Guidance: Usually guided by ductogram or ductoscopy ^[1][2] — a probe or wire is placed in the discharging duct to guide the surgeon to the correct duct
• Indication: Persistent spontaneous discharge from a single duct ^[2]; or biopsy-proven papilloma ^[2]
• Technique: A periareolar incision is made, the discharging duct is identified (often by injecting dye or passing a lacrimal probe), and the duct with its associated lobule is excised en bloc
• Contraindication: Not appropriate if malignancy is strongly suspected (proceed to oncological surgery instead)

• What it involves: Excision of all retroareolar (major) ducts ^[2]
• Indication: Persistent spontaneous discharge when the offending duct cannot be identified (multi-duct discharge); or recurrent discharge after microdochectomy ^[2]
• Consequence: Loss of ability to breastfeed from the affected breast (all major ducts removed), so it is not first-line in young women who wish to breastfeed
• Also indicated: As part of treatment for periductal mastitis with periareolar fistula (total duct excision ± fistulectomy) ^[2]

• Generally does not require surgery ^[2]
• Often resolves spontaneously, sometimes leaving a residual subareolar nodule ^[2]
• Reassurance is key — this is an age-related phenomenon and is NOT associated with increased risk of CA breast ^[2]

• Microdochectomy — indicated if persistent bothersome discharge or nipple inversion is causing functional/cosmetic problems ^[2][4]
• If complicated by periductal mastitis or abscess → treat the infection first (antibiotics, drainage), then consider elective duct excision if recurrent

• Treatment should include excision of the underlying cancer and the nipple-areolar complex ^[2]
• Both mastectomy or BCT followed by whole-breast irradiation are acceptable treatment options ^[2]
• Nipple-areolar sparing mastectomy is CONTRAINDICATED in Paget's disease ^[9][3] — because the disease involves the nipple epidermis; preserving it would leave tumour behind
• Why BCT is acceptable: If the underlying cancer is small and amenable to wide local excision, the nipple-areolar complex is excised along with the tumour, followed by whole-breast radiotherapy. Cosmesis is poor (no nipple), but oncological outcomes are equivalent to mastectomy.

Management depends on the Van Nuys Prognostic Index ^[2]:

Key surgical principles:

• Negative resection margins ≥ 2 mm ^[2] — Why 2 mm? DCIS is famous for "skip lesions" (discontinuous spread along ducts), so a wider margin reduces recurrence. The older 10 mm margin has been abandoned as overly aggressive ^[2].
• Sentinel lymph node biopsy (SLNB) may be considered for DCIS with planned mastectomy or suspicious features — Why? Because if a mastectomy specimen incidentally reveals invasive cancer, SLNB cannot be performed after mastectomy (lymphatic drainage patterns are permanently altered) ^[2]
• ALND is NOT indicated for pure DCIS — DCIS by definition does not invade and therefore cannot metastasise to lymph nodes ^[2]
• Adjuvant hormonal therapy: ER-positive DCIS benefits from tamoxifen (reduces recurrence risk and contralateral cancer risk, but no survival benefit) ^[2]
• No adjuvant chemotherapy for DCIS (no added benefit) ^[2]

The full breast cancer management is beyond the scope of nipple discharge notes, but the key decision tree for the breast is:

Breast Management:

Contraindications to BCS (must know!) ^[3]:

• Multicentric disease (≥ 2 primary tumours in separate quadrants)
• High tumour-to-breast ratio > 20% (can be downstaged by neoadjuvant chemotherapy)
• Tumour too close to NAC
• Persistent positive resection margin
• Diffuse malignant-appearing calcifications on imaging
• Inflammatory breast cancer

Contraindications to radiotherapy ^[3]:

• History of RT to affected chest wall / breast
• Pregnancy (possible to perform BCS in 3rd trimester and defer RT until after delivery)
• Connective tissue disease (e.g. scleroderma, Sjögren's disease) — poor skin healing, risk of fistula formation

Types of mastectomy ^[1][9]:

• Modified radical mastectomy: whole breast + overlying skin + axillary LN (level I + II) ^[3]
• Simple mastectomy: clinically node-negative; axillary LN not dissected → SLNB performed ^[3]
• Skin-sparing mastectomy: preserves overlying breast skin; C/I if inflammatory breast cancer ^[3][9]
• Nipple-areolar sparing mastectomy: preserves NAC dermis/epidermis with removal of major ducts from nipple lumen ^[2][9]. C/I: inflammatory breast cancer, involvement of NAC, nipple retraction, Paget's disease ^[3][9]. For selective low-risk patients; no nipple involvement of cancer; prophylactic mastectomy ^[9]

Axillary Management:

Adjuvant Systemic Therapy — based on St Gallen's IHC subtyping ^[3]:

• Abscess = failure to respond to antibiotics, USG evidence of abscess cavity, or aspiration of pus ^[2]
• Needle aspiration (USG-guided) — when overlying skin is normal (not ischaemic) ^[2]
• Surgical drainage (incision and drainage, I&D) — when there is ischaemia or pressure necrosis of overlying skin, or when abscess is not responsive to antibiotics and needle aspiration ^[2]