Breast Diseases
Surgery · General Surgery · lean revision notes
Breast Diseases
A high-yield surgery + gynaecology crossover topic. The examiner loves the benign vs malignant triage, the triple assessment, TNM staging, BRCA genetics, and the eponymous diseases (Paget's, Mondor's, Phyllodes). Master the age-vs-lump algorithm and you answer most stems instantly.
Surgical & Developmental Classification
Breast lumps and disorders map cleanly onto age — the single most useful discriminator in a clinical vignette.
| Age band | Most likely lesion | Key feature |
|---|---|---|
| 15–25 yr | Fibroadenoma | Highly mobile "breast mouse", firm, painless |
| 25–35 yr | Fibroadenoma / cyclical mastalgia | Hormone-driven |
| 35–45 yr | Fibrocystic change (ANDI) | Lumpy, painful, premenstrual |
| 35–55 yr | Cysts / Phyllodes | Phyllodes is large, rapidly growing |
| >50 yr | Carcinoma until proven otherwise | Hard, fixed, irregular |
High-yield: A discrete, hard, irregular, fixed lump in a woman over 50 is carcinoma until triple assessment proves otherwise. A mobile, smooth, firm lump in a woman under 30 is a fibroadenoma until proven otherwise.
Benign breast disease is increasingly grouped under ANDI — Aberrations of Normal Development and Involution (Hughes classification), spanning fibroadenoma (development), cyclical mastalgia/nodularity (cyclical activity), and cysts/sclerosis (involution).
Benign Breast Diseases
Fibroadenoma
- Benign tumour of the breast lobule; arises from hyperplasia of a single lobule, so technically an aberration of development (ANDI), not a true neoplasm.
- Peak age 15–25 years; commonest breast tumour in young women.
- Firm, smooth, well-encapsulated, extremely mobile → "breast mouse". Painless.
- Types: pericanalicular (older), intracanalicular, and giant fibroadenoma (>5 cm, adolescents).
- Most regress; risk of malignant change is negligible.
High-yield: Management — if <3 cm and FNAC/triple assessment benign in a young woman → **reassurance and observe**. Excision if >3 cm, increasing in size, symptomatic, or patient anxiety.
Phyllodes tumour (Cystosarcoma phyllodes)
- Fibroepithelial tumour, large, rapidly growing, in women aged 40–50 (a decade older than fibroadenoma).
- Leaf-like (Greek phyllon = leaf) architecture; can be benign, borderline or malignant.
- Skin over it may be stretched, shiny with dilated veins, but it rarely involves lymph nodes — malignant phyllodes spreads haematogenously (lungs).
- Treatment: wide local excision with a 1 cm margin (not enucleation — high recurrence). Mastectomy for large/recurrent. Axillary clearance NOT routinely done.
Fibrocystic disease (Fibroadenosis)
- Commonest benign disorder of breast; premenopausal, hormone-dependent.
- Cyclical bilateral lumpiness + mastalgia, worse premenstrually.
- Histology: cysts, apocrine metaplasia, fibrosis, adenosis, epithelial hyperplasia.
- Risk: Only atypical ductal/lobular hyperplasia carries a meaningfully raised cancer risk (~4–5×).
Breast cysts
- Common 35–50 yr. Aspiration is diagnostic and therapeutic.
- Worrying signs after aspiration → biopsy: blood-stained fluid, residual lump, or rapid refilling.
Duct ectasia & Periductal mastitis
- Duct ectasia: dilated subareolar ducts, older/perimenopausal, greenish/cheesy multi-coloured nipple discharge, slit-like nipple retraction.
- Periductal mastitis: younger women, strongly linked to smoking; recurrent periareolar abscess and mammary duct fistula.
Intraductal papilloma
- Commonest cause of blood-stained single-duct nipple discharge in a woman 30–50 yr.
- Solitary, in a major subareolar duct. Treat with microdochectomy (single duct excision).
Mastalgia (Breast pain)
- Cyclical (commoner, related to menstrual cycle) vs non-cyclical.
- First line: reassurance, well-fitting bra, evening primrose oil.
- Refractory cyclical mastalgia → danazol (licensed) or tamoxifen, bromocriptine.
Breast Infections
Lactational (puerperal) breast abscess
- Usually 3rd–4th week of lactation, primigravida.
- Organism: Staphylococcus aureus (entry via cracked nipple).
- Most often in the upper outer quadrant.
Stepwise management: Cellulitis stage → antibiotics (flucloxacillin) + continue breastfeeding/express milk → if abscess forms (fluctuant, USG confirms) → USG-guided needle aspiration (first line in modern practice) → incision & drainage if multiloculated, skin compromised, or aspiration fails.
High-yield: Non-lactational/recurrent subareolar abscess in a young woman who smokes = periductal mastitis; it tends to recur and may form a mammary fistula needing fistulectomy.
Mondor's disease
- Thrombophlebitis of superficial veins of the breast/chest wall (thoraco-epigastric vein).
- Palpable tender subcutaneous cord; self-limiting. Reassurance ± NSAIDs.
Breast Carcinoma
Risk factors
Think prolonged unopposed oestrogen exposure:
- Early menarche (<12), late menopause (>55), nulliparity, late first pregnancy (>30).
- Age, family history, BRCA1/BRCA2 mutations, prior breast/endometrial cancer.
- HRT, obesity (postmenopausal), alcohol, radiation exposure.
- Protective: early full-term pregnancy, breastfeeding, multiparity, early menopause/oophorectomy.
BRCA genetics (favourite exam fact)
| Gene | Chromosome | Lifetime breast cancer risk | Other cancers |
|---|---|---|---|
| BRCA1 | 17q | 60–80% | Ovarian (high), triple-negative/basal breast Ca |
| BRCA2 | 13q | 45–70% | Ovarian, male breast cancer, prostate, pancreatic |
High-yield: BRCA1 → chromosome 17, associated with triple-negative cancers and high ovarian risk. BRCA2 → chromosome 13, classically linked to male breast cancer. Both are tumour-suppressor genes (DNA repair), autosomal dominant. Prophylactic bilateral mastectomy + risk-reducing salpingo-oophorectomy markedly cut risk.
Pathology types
- Non-invasive: DCIS (ductal carcinoma in situ — confined within basement membrane, often microcalcifications on mammography, "comedo" type most aggressive); LCIS (lobular carcinoma in situ — a marker of bilateral risk, not a true precursor).
- Invasive: Invasive ductal carcinoma (NST, "no special type") is commonest (~70–80%). Invasive lobular carcinoma is more often bilateral/multifocal ("Indian-file" pattern, E-cadherin negative).
- Special types: medullary, mucinous (colloid), tubular, papillary — generally better prognosis.
- Inflammatory carcinoma: peau d'orange, erythema, warmth; dermal lymphatic invasion; worst prognosis, treated as locally advanced (T4d).
Paget's disease of the nipple
- Eczema-like, unilateral, destructive lesion of the nipple spreading to areola; itching, ulceration, nipple destruction.
- Underlying DCIS or invasive carcinoma in ~90%+.
- Histology: large pale Paget cells with halo in the epidermis.
High-yield differentiator: Eczema starts on the areola, spares the nipple, is bilateral, and responds to steroids. Paget's starts on the nipple, destroys it, is unilateral, and does not respond to steroids → mandatory biopsy.
Clinical Features & Examination
- Lump — hard, irregular, fixed, non-tender.
- Skin signs: dimpling/tethering (Cooper's ligament involvement), peau d'orange (cutaneous lymphatic oedema), ulceration, nipple retraction/destruction.
- Nipple discharge — bloody (papilloma, carcinoma), multicoloured (duct ectasia).
- Axillary/supraclavicular lymphadenopathy.
- Tethering tests: ask patient to press hands on hips (pectoral fixation) and raise arms (skin tethering becomes obvious).
High-yield: Commonest site of breast carcinoma is the upper outer quadrant (most breast tissue + axillary tail of Spence). Commonest presenting symptom is a painless lump.
Triple Assessment — the diagnostic backbone
Every suspicious breast lump → triple assessment (sensitivity >99.6% when all three concordant):
1. Clinical examination → 2. Imaging → 3. Pathology (core biopsy)
| Component | <35 yr / dense breast | >35 yr |
|---|---|---|
| Imaging of choice | Ultrasound | Mammography (+ USG) |
| Pathology | Core needle biopsy (preferred over FNAC) | Core needle biopsy |
- Mammography: screening view = craniocaudal + mediolateral oblique. Malignant signs → spiculated mass, microcalcifications, architectural distortion. Used >35–40 yr (dense young breast is radio-opaque, low yield).
- USG: investigation of choice in young/dense breast and pregnancy; distinguishes solid vs cystic.
- MRI: for BRCA screening, lobular cancer extent, implants, occult primary.
- Core biopsy > FNAC because it distinguishes in-situ from invasive disease and allows ER/PR/HER2 receptor testing.
High-yield: Investigation of choice in a young woman with dense breasts = ultrasound. Screening modality for the general population (>40–50 yr) = mammography. Reporting uses BI-RADS (0–6); BI-RADS 4–5 needs biopsy.
TNM Staging (AJCC, simplified)
| T | Definition |
|---|---|
| Tis | Carcinoma in situ (DCIS) / Paget's without tumour |
| T1 | ≤ 2 cm |
| T2 | > 2–5 cm |
| T3 | > 5 cm |
| T4 | Any size with chest wall (T4a) / skin: oedema, peau d'orange, ulceration (T4b) / both (T4c) / inflammatory (T4d) |
| N | Definition |
|---|---|
| N1 | Mobile ipsilateral axillary nodes |
| N2 | Fixed/matted axillary nodes |
| N3 | Infraclavicular / internal mammary / supraclavicular nodes |
- M1 = distant metastasis. Commonest sites: bone > lung > liver > brain.
- Stage grouping mnemonic for nodes: N1 mobile, N2 fixed, N3 above (supraclavicular/infraclavicular).
High-yield: Most important prognostic factor in operable breast cancer = axillary lymph node status. ER/PR positivity predicts response to hormone therapy; HER2 positivity indicates trastuzumab benefit; triple-negative has the worst prognosis.
Management
Treatment is multimodal — surgery, radiotherapy, chemotherapy, hormonal therapy, targeted therapy — guided by stage and receptor status.
Surgery of the breast
- Breast Conserving Surgery (BCS) / wide local excision + whole-breast radiotherapy — for early, smaller tumours with favourable tumour:breast ratio. Survival is equal to mastectomy when combined with radiotherapy.
- Mastectomy — for large/multifocal tumours, contraindications to radiotherapy, or patient choice.
Types of mastectomy:
| Procedure | What is removed |
|---|---|
| Simple/total mastectomy | Whole breast, no axillary clearance (used in DCIS, with SLNB) |
| Modified Radical Mastectomy (Patey) | Breast + axillary clearance; removes pectoralis minor, preserves pectoralis major |
| Auchincloss / Madden | Breast + axillary clearance; both pectoral muscles preserved |
| Halsted radical mastectomy | Breast + both pectoral muscles + axillary contents (now largely historical) |
High-yield: Patey (MRM) removes pectoralis minor but spares pectoralis major. Auchincloss/Madden spares both pectoral muscles. Halsted (now obsolete) removes both.
Axillary management
- Sentinel Lymph Node Biopsy (SLNB) — standard in a clinically node-negative axilla; uses blue dye (isosulfan/methylene blue) + radioisotope (technetium-99m sulphur colloid). Avoids morbidity of full clearance.
- Axillary clearance (levels I–III, relative to pectoralis minor) — if nodes clinically/SLNB positive.
- Complications of clearance: lymphoedema, seroma, winged scapula (long thoracic nerve → serratus anterior), loss of latissimus function (thoracodorsal nerve), intercostobrachial nerve injury (numb upper inner arm).
High-yield: Damage to the long thoracic nerve (of Bell) during axillary surgery → winged scapula (serratus anterior palsy). Thoracodorsal nerve supplies latissimus dorsi.
Adjuvant therapy
- Radiotherapy: mandatory after BCS; after mastectomy if T3/T4, ≥4 positive nodes, or positive margins.
- Chemotherapy: anthracycline + taxane regimens (e.g., AC-T); for node-positive, high-grade, triple-negative, HER2+ disease.
- Hormonal therapy (ER/PR positive):
- Premenopausal → Tamoxifen (SERM) ×5–10 yr.
- Postmenopausal → Aromatase inhibitors (anastrozole, letrozole, exemestane).
- Targeted (HER2 positive) → Trastuzumab (Herceptin) ± pertuzumab; monitor for cardiotoxicity.
High-yield: Tamoxifen side effects — increased endometrial carcinoma and DVT/VTE risk; protective on bone in postmenopausal women. Aromatase inhibitors cause osteoporosis/arthralgia. Trastuzumab → cardiomyopathy (check ejection fraction).
Complications
- Local: lymphoedema (most feared after axillary clearance — can lead to Stewart-Treves syndrome = lymphangiosarcoma in chronic lymphoedema), chest-wall recurrence, seroma, flap necrosis.
- Metastatic: bone (pathological fracture, hypercalcaemia, cord compression), lung, liver, brain.
- Treatment-related: tamoxifen → endometrial Ca/VTE; AIs → osteoporosis; trastuzumab → cardiotoxicity; radiation → pneumonitis, secondary angiosarcoma.
Key Differentials of a Breast Lump
| Feature | Fibroadenoma | Phyllodes | Cyst | Carcinoma |
|---|---|---|---|---|
| Age | 15–25 | 40–50 | 35–50 | >50 |
| Growth | Slow | Rapid | Variable | Progressive |
| Surface | Smooth, mobile | Bosselated, mobile | Smooth, fluctuant | Hard, irregular, fixed |
| Skin signs | None | Stretched/shiny | None | Dimpling, peau d'orange |
| Nodes | No | Rare | No | Often present |
| Treatment | Observe/excise | WLE 1 cm margin | Aspirate | Multimodal |
Other differentials: galactocele (lactating), fat necrosis (post-trauma, mimics cancer radiologically), lipoma, gynaecomastia (males).
Recently asked / exam angle
- BRCA1 = chromosome 17, triple-negative; BRCA2 = chromosome 13, male breast cancer — repeatedly tested one-liners.
- Patey's MRM removes pectoralis minor (sparing major); Auchincloss spares both — classic surgery MCQ.
- Sentinel node identified by blue dye + radioisotope (Tc-99m) in node-negative axilla.
- Paget's vs eczema: nipple-first/unilateral/biopsy vs areola-first/bilateral/steroids.
- Most common site = upper outer quadrant; most common mets = bone.
- Investigation of choice in young dense breast/pregnancy = USG; in older = mammography (spiculated mass + microcalcifications).
- Tamoxifen → endometrial carcinoma + VTE; premenopausal hormone therapy of choice.
- Long thoracic nerve injury → winged scapula in axillary clearance.
- Triple-negative breast cancer = ER−/PR−/HER2−, worst prognosis, no targeted hormonal benefit.
- Inflammatory carcinoma = T4d, peau d'orange, dermal lymphatic invasion, worst prognosis.
Rapid revision
- Fibroadenoma = "breast mouse", 15–25 yr, mobile, observe if <3 cm.
- Phyllodes = leaf-like, rapid, 40–50 yr; treat with WLE + 1 cm margin, no axillary clearance.
- Triple assessment = clinical exam + imaging + core biopsy; concordance >99% accurate.
- USG for young/dense/pregnant breast; mammography (spiculated mass, microcalcification) for >40.
- Core biopsy > FNAC — it distinguishes in-situ from invasive and gives ER/PR/HER2 status.
- BRCA1 → ch17, triple-negative, ovarian; BRCA2 → ch13, male breast cancer — both tumour suppressors, autosomal dominant.
- Commonest invasive type = invasive ductal (NST); lobular is bilateral, E-cadherin negative, Indian-file.
- Axillary node status = most important prognostic factor; bone = commonest metastatic site.
- Patey MRM removes pectoralis minor; Auchincloss/Madden spare both pectorals; Halsted removes both (obsolete).
- SLNB for clinically node-negative axilla (blue dye + Tc-99m); long thoracic nerve injury → winged scapula.
- Premenopausal ER+ → tamoxifen (endometrial Ca/VTE risk); postmenopausal → aromatase inhibitors (osteoporosis); HER2+ → trastuzumab (cardiotoxicity).
- Paget's = unilateral nipple destruction with underlying carcinoma; lactational abscess = S. aureus, 3rd–4th week, aspirate ± I&D, continue breastfeeding.