Ch17: Breast Disease（乳腺疾病）

Preparatory Mindset

Breast disease spans benign disorders (mastitis, fibrocystic change, fibroadenoma), breast cancer (the main surgical focus), and nipple discharge. The lecture (Zhangqing, 25KB, 117 slides) covers surgical anatomy, benign disease, and the full breast cancer pathway — presentation, spread, diagnosis (triple assessment), staging, and surgical treatment (breast-conserving vs mastectomy + SLNB).

Exam mindset: triple assessment (clinical exam + imaging + biopsy), the sentinel node concept, breast cancer staging/receptor status (ER/PR/HER2), and the surgical options (lumpectomy + RT vs mastectomy) are the core. Acute mastitis (Staph aureus, lactating) and its drainage (radial incision) are lab-style OSCE topics.

Core Concepts

1. Surgical anatomy (MUST KNOW)

- Axillary groups: lateral (along axillary vein), anterior (along lateral thoracic vessels — receives most breast lymph), posterior (subscapular), central, interpectoral (Rotter), apical (above pectoralis minor) - Internal mammary nodes: along the internal mammary vessels (medial breast) - Sentinel node = the first node draining the tumor area — removed for staging (SLNB)

• Position: 2nd-6th ribs, sternum to anterior axillary line; tail of Spence → axilla
• Lobules → 15-20 lactiferous ducts → ampulla → nipple; Montgomery's tubercles (areolar sebaceous glands)
• Cooper's (suspensory) ligaments: fibrous projections from superficial fascia to skin — tethering/dimpling over a carcinoma ("peau d'orange" when infiltrated)
• Lymphatic drainage (MUST KNOW): predominantly to the axillary (85%) and internal mammary nodes

2. Triple assessment (MUST KNOW)

- Mammography: screening tool; sensitivity ↑ with age (less dense breast); malignant features: spiculated mass, microcalcifications (pleomorphic/clustered), architectural distortion; benign: coarse/popcorn calcifications; BI-RADS classification (1-6) - Ultrasound: young women (dense breast), distinguishes cyst (simple anechoic) from solid; characterizes borders (spiculated = malignant), posterior shadowing (malignant) vs enhancement (cyst/benign) - MRI: high-risk screening, extent assessment

1. Clinical examination (history + exam)
2. Imaging:
3. Biopsy (tissue diagnosis): FNA (cytology), core needle biopsy (CNB) (histology + receptors), excisional biopsy; sentinel node biopsy

• Triple assessment concordance required; normal imaging does NOT exclude cancer

3. Benign breast disease (MUST KNOW)

- Lactating women; Staphylococcus aureus most common; via cracked/sore nipple; duct obstruction → stasis → infection - Clinical: fever, painful swollen breast, erythema — early cellulitis, later abscess (fluctuance = late sign) - Treatment: cellulitis stage → antibiotics (flucloxacillin) + local heat + analgesia + continue breastfeeding/empty the breast; abscess (48 h no response) → repeated aspiration under antibiotic cover (preserves breastfeeding) or operative drainage: radial incision over the affected segment, break loculations, pack with gauze, culture the pus

• Fibrocystic change (乳腺囊性增生病): most common benign condition; pain & lumpiness with menstrual cycle; hormone-driven; reassurance, analgesia, exclude cancer (biopsy if suspicious)
• Fibroadenoma (纤维腺瘤): most common benign tumor in young women (15-35); smooth, mobile ("breast mouse"), well-defined; US/core biopsy; excision if large/growing; no malignant potential
• Acute bacterial mastitis (急性乳腺炎) — MUST KNOW:
• Traumatic fat necrosis: mimics carcinoma (lump after trauma) → biopsy to exclude
• Duct ectasia/periductal mastitis: smokers; nipple discharge (any colour), subareolar mass
• Mondor's disease: thrombophlebitis of a superficial breast/chest-wall vein (cord-like); self-limited
• Nipple discharge: blood (carcinoma, duct ectasia, fibrocystic), black/green (duct ectasia), purulent (infection), serous (fibrocystic/carcinoma), milky (lactation) — blood-stained single-duct discharge → exclude carcinoma (cytology, ductography, microdochectomy)

4. Breast cancer — epidemiology & risk factors (MUST KNOW)

• Most common female cancer worldwide
• Risk factors: female sex, age, family history (BRCA1/2), early menarche/late menopause, nulliparity/late first pregnancy, no breastfeeding, hormone replacement therapy, alcohol, obesity, prior breast cancer/atypia; radiation; (Li-Fraumeni, Lynch)
• BRCA1/2: hereditary breast & ovarian cancer; also male breast cancer; prophylactic mastectomy/oophorectomy consideration

5. Breast cancer — clinical features & spread (MUST KNOW)

- Lymphatic: axillary (85%) & internal mammary — axillary node status = most important prognostic factor - Hematogenous: bone (most common), liver, lung, brain - Direct: skin, pectoral muscle, chest wall (fixation)

• Presentation: painless lump (most common), nipple changes (retraction, discharge, eczema — Paget's disease), skin changes (peau d'orange, dimpling, ulceration), axillary lymphadenopathy, inflammatory breast cancer (diffuse erythema/edema — aggressive)
• Spread:
• Paget's disease: eczema-like nipple change with underlying ductal carcinoma in situ/invasive
• Inflammatory breast cancer (IBC): diffuse erythema, edema (peau d'orange), warm — no discrete mass; aggressive; treat with neoadjuvant chemo first

6. Breast cancer — staging & receptors (MUST KNOW)

• TNM staging (8th ed.): T (size/invasion: T1 ≤2 cm, T2 2-5, T3 >5, T4 chest wall/skin), N (nodes: N0, N1mi, N1-3), M (metastasis)
• Prognostic factors: axillary node status (most important), tumor size, grade, receptor status, HER2, Ki-67, lymphovascular invasion, age
• Receptors (MUST KNOW): ER/PR (hormone receptor) status → endocrine therapy (tamoxifen/aromatase inhibitors); HER2 (ERBB2) status → trastuzumab (Herceptin); triple-negative (ER-/PR-/HER2-) → chemotherapy-based, worse prognosis

7. Breast cancer — treatment (MUST KNOW)

- Breast-conserving surgery (BCS/lumpectomy + radiotherapy): for early cancer (tumor:breast ratio favorable, no multicentricity) — survival EQUAL to mastectomy + RT - Mastectomy: total (simple), modified radical (mastectomy + axillary node clearance — standard for invasive when BCS not suitable); radical (Halsted — historical, no longer); skin-sparing/nipple-sparing for reconstruction - Axillary staging: sentinel lymph node biopsy (SLNB) for clinically node-negative (blue dye ± isotope, gamma probe); axillary lymph node dissection (ALND) if sentinel positive (or clinically node-positive)

- Endocrine: tamoxifen (premenopausal), aromatase inhibitors (postmenopausal) for ER+ - Chemotherapy: anthracycline/taxane regimens; neoadjuvant for large/inflammatory/triple-negative/HER2+ - Anti-HER2: trastuzumab (+ pertuzumab) for HER2+ - Radiotherapy: after BCS (mandatory), post-mastectomy (high risk: T3/T4, N+), chest wall + nodes

• Surgery:
• Adjuvant/neoadjuvant systemic:
• Metastatic disease: palliative — systemic therapy per receptors, local control, bone protection (bisphosphonates), symptom control
• Follow-up: surveillance, contralateral breast screening, recurrence detection

High-Yield Points

• Triple assessment: clinical + imaging (mammogram/US) + biopsy (core) — normal imaging doesn't exclude cancer
• Lymphatics: axillary 85% + internal mammary; axillary groups: lateral, anterior, posterior, central, interpectoral, apical; sentinel = first node
• Acute mastitis: Staph aureus, lactating, cracked nipple; antibiotics (flucloxacillin) + empty breast; abscess → aspiration or radial drainage
• Cooper's ligaments → dimpling/peau d'orange
• Breast cancer: painless lump; Paget (nipple eczema); inflammatory (diffuse erythema — aggressive)
• Prognosis: axillary node status #1; receptors ER/PR/HER2 drive treatment; triple-negative worse
• BCS + RT = equal survival to mastectomy; SLNB for staging (blue dye/isotope)
• Endocrine: tamoxifen (pre)/AI (post); HER2+: trastuzumab; neoadjuvant chemo for large/inflammatory/TN
• Screening: mammography (CC + MLO views)
• Most common benign tumors: fibroadenoma (young); fibrocystic change (pain/lumpiness)

Topic Summary

Breast disease: anatomy (15-20 ducts, Cooper's ligaments, axillary 85% drainage), triple assessment (exam + mammogram/US + core biopsy). Benign: fibrocystic change, fibroadenoma (young, mobile), acute mastitis (Staph aureus, lactating — antibiotics, empty breast; abscess → radial incision/aspiration), fat necrosis, duct ectasia, nipple discharge (blood → exclude cancer). Breast cancer: risk (BRCA, HRT, age), presentation (painless lump, Paget, inflammatory), spread (axillary nodes → most important prognosis; bone/liver/lung), staging (TNM), receptors (ER/PR/HER2; triple-negative worse). Treatment: BCS + RT = mastectomy (equal survival); SLNB/ALND; endocrine (tamoxifen/AI), chemo (neo/adjuvant), trastuzumab (HER2+), RT. Sentinel node concept and receptor-driven therapy are the modern core.