Surgical Breast Disease
A Step 2 CK–focused surgical breast lesson covering triple assessment and age-based workup, benign lesions, breast cancer types, and next-best-step management from palpable mass and nipple discharge through inflammatory breast cancer, receptors, and axillary staging.
The Board Framework: Triple Assessment
Surgical breast disease spans benign lumps, high-risk lesions, and invasive cancer — and the boards test how you work up a breast complaint and choose the next best step. Every palpable mass or abnormal mammogram gets triple assessment: clinical exam + imaging + tissue biopsy. When all three are concordantly benign, reassure; any discordance mandates excision.
Imaging is age-driven. Under ~30 years, start with ultrasound; at ~30 and older, get diagnostic mammography ± ultrasound. Tissue is obtained by core-needle biopsy — it yields histology, grade, and ER/PR/HER2 receptors, and is preferred over FNA (which cannot distinguish invasive from in-situ disease).
Key trap: a dominant hard, fixed, or irregular mass — or a suspicious mammogram (spiculation, clustered pleomorphic microcalcifications) — is cancer until proven otherwise and must be biopsied even if imaging looks benign.
- Palpable mass, <30 yo: ultrasound first → simple cyst = aspirate/reassure; solid = core biopsy
- Palpable mass, ≥30 yo: diagnostic mammogram + ultrasound, then core biopsy
- Core-needle biopsy > FNA (gives grade, invasion status, ER/PR/HER2)
- Fibroadenoma: young woman; mobile, rubbery, well-circumscribed "breast mouse"
- Phyllodes tumor: rapidly enlarging; treat with wide local excision, no sentinel node (spreads hematogenously)
- Intraductal papilloma: #1 cause of bloody, unilateral, single-duct nipple discharge
- Fat necrosis: prior trauma/surgery/seatbelt; can mimic cancer on imaging → biopsy
- Inflammatory breast cancer: peau d'orange + erythema; dermal lymphatic invasion; neoadjuvant chemo first
- Paget disease of nipple: eczematous/ulcerated nipple = underlying DCIS or invasive cancer
- LCIS: risk marker for bilateral future cancer (not a direct precursor) → surveillance ± chemoprevention
Benign & Discharge-Causing Lesions
| Lesion | Classic clue | Next step / management |
|---|---|---|
| Fibroadenoma | Young woman; mobile, rubbery, well-circumscribed | US; core biopsy if unclear; observe or excise if large/growing |
| Simple cyst | Fluctuates with menstrual cycle | US; aspirate if symptomatic; biopsy if complex (solid/mural component) |
| Phyllodes tumor | Large, rapidly growing mass | Wide local excision (~1 cm margins); no SLNB |
| Intraductal papilloma | Bloody, single-duct discharge | Duct excision (rule out carcinoma) |
| Fat necrosis | Prior trauma / surgery / seatbelt | Core biopsy to exclude cancer |
| Duct ectasia | Green/multicolored discharge, periareolar | Reassure; excision if persistent |
| Lactational abscess | Breastfeeding; S. aureus | Aspiration/I&D + antibiotics; continue nursing |
A 52-year-old woman has a rapidly enlarging, red, warm breast over 3 weeks with skin thickening and dimpling (peau d'orange). She is afebrile and did not improve on a course of antibiotics.
Diagnosis: Inflammatory breast cancer (T4d) — obstruction of dermal lymphatics by tumor, not infection.
Next best step: skin punch biopsy + core biopsy of the breast (confirm dermal lymphatic invasion and receptors), plus staging imaging.
Treatment (trimodal): neoadjuvant chemotherapy → modified radical mastectomy → radiation (add trastuzumab if HER2+, endocrine therapy if ER+). Breast-conserving therapy is contraindicated.
Board trap: breast erythema that fails to respond to antibiotics is cancer until proven otherwise — do not keep treating it as mastitis.
(1) A 38-year-old woman has spontaneous bloody discharge from a single duct of one breast; no mass, and mammogram/US are negative. → Intraductal papilloma (most common cause). Next step: imaging then surgical duct excision to exclude carcinoma.
(2) A 24-year-old has a firm, mobile, well-circumscribed 2-cm mass; US shows a solid mass with benign features. Next step: core-needle biopsy; if fibroadenoma and concordant, observe (excise if large, growing, or symptomatic).
(3) A 46-year-old develops a firm mass after a seatbelt injury; mammogram shows calcifications. Next step: core biopsy — fat necrosis mimics malignancy, so confirm histology rather than assuming trauma.
(4) A 60-year-old has a scaly, eczematous nipple unresponsive to steroid cream. → Paget disease → full-thickness nipple biopsy + mammogram to find underlying carcinoma.
- Breast-conserving therapy (lumpectomy + whole-breast radiation) gives survival equal to mastectomy for eligible early cancers
- BCT contraindicated: multicentric disease, prior chest radiation, pregnancy (can't irradiate — esp. 1st/2nd trimester), diffuse malignant microcalcifications, persistently positive margins, inflammatory cancer
- Axilla: clinically node-negative → sentinel lymph node biopsy; clinically/grossly positive nodes → axillary dissection
- Receptors drive systemic therapy: ER/PR+ → endocrine therapy — tamoxifen (premenopausal), aromatase inhibitor (postmenopausal); HER2+ → trastuzumab; triple-negative → chemotherapy
- DCIS: lumpectomy + radiation (or mastectomy); add SLNB if mastectomy; endocrine therapy if ER+
- Screening (USPSTF 2024): biennial mammography, ages 40–74
Bone is the most common site of distant metastasis in breast cancer (followed by lung, liver, and brain).
Classic mnemonic for the primary tumors that most often metastasize to bone — "BLT with a Kosher Pickle":
- B — Breast
- L — Lung
- T — Thyroid
- K — Kidney
- P — Prostate
Board tie-in: new back pain, pathologic fracture, or hypercalcemia in a treated breast-cancer patient = bone metastasis until proven otherwise. Breast bone lesions may be osteolytic, osteoblastic, or mixed.
DCIS vs LCIS
| Feature | DCIS | LCIS |
|---|---|---|
| Nature | True precursor — can progress to invasive cancer | Risk marker for future cancer |
| Mammogram | Clustered pleomorphic microcalcifications | Usually incidental on biopsy (no calcifications) |
| Cancer risk | Mainly ipsilateral | Both breasts (bilateral) |
| Management | Lumpectomy + radiation (or mastectomy); SLNB if mastectomy; endocrine if ER+ | Surveillance ± chemoprevention (tamoxifen/AI); routine wide excision not required for classic LCIS |
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