Female Reproductive & Breast

Breast mass: workup algorithm

Clinical Overview and When to Suspect Breast Mass

— Up to 16% of women aged 40–69 will present with a breast complaint over a 10-year span; most masses are benign (fibroadenoma, cyst, fibrocystic change), but lifetime invasive breast cancer risk is ~13% in US women.

— Median age at diagnosis of breast cancer is 62; however, dense breasts, BRCA1/2 carriers, and Ashkenazi Jewish ancestry shift suspicion earlier.

— Hard, fixed, irregular, non-tender mass

— Associated skin dimpling, peau d'orange, nipple retraction, bloody/unilateral nipple discharge, or axillary lymphadenopathy

— Mass that persists after one menstrual cycle in a premenopausal woman

— Any palpable mass in a postmenopausal woman is cancer until proven otherwise

— Prior chest wall radiation (e.g., Hodgkin lymphoma in adolescence)

— Strong family history (first-degree relative with premenopausal breast/ovarian cancer)

— Known BRCA1/2, PALB2, TP53, CDH1, PTEN pathogenic variants

— Prior atypical hyperplasia or LCIS on biopsy

Definition: A discrete, palpable lesion in the breast that is distinct from surrounding tissue, persistent across menstrual cycles, or identified incidentally on imaging.

Epidemiology and stakes:

When to suspect malignancy in a palpable mass:

High-risk patient categories (lower threshold to image and biopsy):

Step 3 management: Every palpable mass deserves a structured triple assessment — clinical exam, age-appropriate imaging, and tissue sampling when indicated. A negative mammogram does NOT exclude cancer in a palpable mass; up to 15% of cancers are mammographically occult, especially in dense breasts.

Board pearl: The question stem cue "her mammogram 6 months ago was normal" is a trap — a clinically suspicious palpable mass still requires diagnostic imaging plus biopsy regardless of prior screening results.

Presentation Patterns and Key History

— Self-discovered lump (most common; 70% of breast cancers are self-detected)

— Mass found on clinician breast exam

— Imaging-detected mass (BI-RADS 4/5 on screening) — not "palpable" but workup overlaps

— Associated nipple discharge, skin change, or breast pain

— Duration and change over time (stable vs. growing; cyclic vs. fixed)

— Relation to menstrual cycle (premenstrual fullness suggests fibrocystic)

— Pain character (cancer typically painless; mastitis/abscess painful)

— Nipple discharge: unilateral, single-duct, spontaneous, bloody = worrisome; bilateral, multi-duct, milky = usually benign/prolactin-related

— Skin/nipple change: retraction, eczema-like changes (think Paget disease), erythema, peau d'orange

— Trauma history (fat necrosis mimics cancer)

— Lactation status (postpartum mastitis, galactocele)

— Constitutional symptoms (weight loss, bone pain → metastatic workup)

— Reproductive: early menarche (<12), late menopause (>55), nulliparity, first live birth >30, no breastfeeding

— Hormonal: combined HRT >5 years, current OCP use (small risk)

— Lifestyle: alcohol ≥1 drink/day, obesity (postmenopausal), physical inactivity

— Family history: age of onset, bilateral disease, male breast cancer, ovarian/pancreatic/prostate cancer (BRCA spectrum)

— Personal: prior breast biopsies showing atypia, dense breasts, chest radiation age 10–30

Chief complaint patterns:

Targeted history — the 8 essential questions:

Risk factor inventory:

Key distinction: Cyclic, bilateral, diffuse tenderness with nodularity = fibrocystic change (reassure, recheck after next cycle). Discrete, persistent, unilateral mass = needs imaging regardless of age.

Board pearl: Document a 5-generation pedigree if family history is suggestive; this drives genetic counseling referrals and changes screening from age 40 mammography to age 25–30 MRI-based surveillance for BRCA carriers.

Physical Exam Findings

— Examine in both upright and supine positions; supine flattens breast over chest wall improving detection of deep masses

— Inspect with arms relaxed, then raised, then hands pressing hips (pectoral contraction reveals skin tethering)

— Palpate all four quadrants plus tail of Spence using vertical strip pattern, three pressure levels (light/medium/deep)

— Examine axillary, supraclavicular, and infraclavicular nodes

— Smooth, mobile, well-circumscribed, rubbery → fibroadenoma (typically age 15–35)

— Soft, mobile, tender, fluctuant → simple cyst (typically age 35–50, perimenopausal)

— Tender, diffuse, nodular, bilateral, cyclical → fibrocystic change

— Tender, warm, erythematous, fluctuant, postpartum → abscess/mastitis

— Hard consistency (like a knuckle, not a lip or nose)

— Fixed to skin or chest wall

— Irregular borders

— Non-tender (most cancers are painless)

— Skin changes: dimpling, retraction, peau d'orange, ulceration

— Nipple changes: retraction, deviation, eczematous scaling (Paget disease)

— Palpable, firm, fixed axillary nodes upstage disease and change management

— Supraclavicular adenopathy = N3 disease (stage IIIC) — independently changes prognosis and treatment plan

— Diffuse erythema involving >1/3 of breast, rapid onset (<6 months), peau d'orange, often no discrete mass

— Frequently misdiagnosed as mastitis — mastitis that fails to resolve after 1–2 weeks of antibiotics demands biopsy (skin punch biopsy showing dermal lymphatic invasion is diagnostic)

Setting and technique:

Benign-feeling features:

Malignant-feeling features ("the 6 hard signs"):

Lymph node assessment:

Inflammatory breast cancer red flags:

Step 3 management: Document mass location by clock position and distance from nipple, plus size in two dimensions — this enables imaging correlation and longitudinal comparison. CCS pearl: Always order ipsilateral axillary ultrasound when imaging a suspicious mass — nodal status changes everything downstream.

Diagnostic Workup — Initial Imaging

— Age <30: Ultrasound first. Dense fibroglandular tissue limits mammography sensitivity; ionizing radiation is undesirable in young dense tissue. Add diagnostic mammogram if US suspicious or if there is a strong family history.

— Age ≥30: Diagnostic mammogram + targeted ultrasound (not screening mammogram — diagnostic includes additional views and spot compression).

— Pregnant/lactating any age: Ultrasound first; mammography is safe with abdominal shielding if needed but US is preferred initial test.

— Simple cyst: anechoic, posterior acoustic enhancement, thin wall → no further workup if asymptomatic; aspirate only if symptomatic or recurrent

— Complicated cyst (internal echoes, no solid component): short-interval follow-up vs aspiration

— Complex cystic and solid: biopsy

— Solid mass: assess shape, margins, orientation, posterior features → biopsy if not clearly benign

— Spiculated margins, microcalcifications (pleomorphic, linear-branching, fine granular), architectural distortion, asymmetric density, skin thickening

— 0: Incomplete, need additional imaging

— 1: Negative — routine screening

— 2: Benign — routine screening

— 3: Probably benign (<2% malignancy) — 6-month follow-up imaging

— 4 (A/B/C): Suspicious (2–95%) — tissue biopsy

— 5: Highly suggestive of malignancy (>95%) — biopsy

— 6: Known biopsy-proven malignancy

Age-based imaging algorithm (the core Step 3 decision):

Ultrasound findings and interpretation:

Mammographic features favoring malignancy:

BI-RADS categories drive next step:

Board pearl: A palpable mass in a woman ≥30 gets BOTH diagnostic mammogram AND ultrasound — they are complementary, not alternatives. Mammogram detects calcifications and assesses contralateral breast; US characterizes the palpable lesion and guides biopsy.

Step 3 management: Do not order MRI as the initial test for a palpable mass — MRI has high sensitivity but lower specificity and is reserved for high-risk screening, occult primary, or pre-op extent-of-disease evaluation.

Diagnostic Workup — Tissue Sampling and Confirmatory Studies

— Core needle biopsy (CNB) with image guidance — first-line for solid masses. Provides histology, allows ER/PR/HER2 testing, distinguishes invasive from in situ disease. US-guided for sonographically visible lesions; stereotactic for calcifications only seen on mammogram; MRI-guided for MRI-only lesions.

— Fine needle aspiration (FNA): Cytology only — cannot distinguish invasive from in situ, cannot reliably do receptor testing. Acceptable for cyst aspiration or suspicious lymph nodes, but not preferred for primary mass diagnosis.

— Excisional biopsy: When CNB is non-diagnostic, discordant, or shows high-risk lesion (ADH, LCIS, radial scar, papilloma) requiring full excision.

— Simple cyst, asymptomatic → leave alone

— Simple cyst, symptomatic → aspirate; if fluid is clear/straw/green and mass fully resolves, no further workup

— Bloody aspirate, residual mass after aspiration, or recurrence within weeks → send fluid for cytology and proceed to core biopsy

— ER, PR, HER2 (IHC; HER2 equivocal → reflex FISH)

— Ki-67 proliferation index

— Histologic grade, lymphovascular invasion

— Oncotype DX or MammaPrint for ER+/HER2-/node-negative cases to guide chemotherapy decisions

— Cancer diagnosed at age ≤50, triple-negative ≤60, male breast cancer, bilateral disease, ≥2 primary cancers, Ashkenazi Jewish ancestry, family history meeting NCCN criteria

Triple test concordance: Clinical exam + imaging + tissue sampling. All three must agree as benign to safely defer biopsy/excision; any discordance → excisional biopsy.

Biopsy modalities (ranked by preference):

Cyst aspiration logic:

Pathology elements to request on confirmed cancer:

Genetic testing referral triggers:

Board pearl: Core needle biopsy reading "atypical ductal hyperplasia" requires surgical excision because 15–20% are upgraded to DCIS/invasive cancer on final pathology.

CCS pearl: Order biopsy as "US-guided core needle biopsy" — specifying modality and guidance shows you understand the workflow.

Risk Stratification and Management Logic

— All three benign and concordant (e.g., young woman, US shows fibroadenoma features, CNB confirms fibroadenoma) → reassure, optional 6-month US follow-up to confirm stability

— Discordant (any "suspicious" element) → excisional biopsy

— Malignant on biopsy → staging and multidisciplinary referral

— Atypical ductal hyperplasia (ADH): surgical excision; if confirmed, qualifies for risk-reduction tamoxifen/raloxifene and enhanced surveillance

— Atypical lobular hyperplasia (ALH) / classic LCIS: surveillance + chemoprevention discussion; pleomorphic LCIS → excise

— Flat epithelial atypia, radial scar, intraductal papilloma: typically excise

— Gail model (Breast Cancer Risk Assessment Tool) estimates 5-year invasive risk

— 5-year risk ≥1.67% in women ≥35 qualifies for tamoxifen (pre- or postmenopausal) or raloxifene/aromatase inhibitor (postmenopausal only) for primary prevention

— Tyrer-Cuzick or BRCAPRO for hereditary risk → genetic counseling, possible MRI surveillance, risk-reducing surgery

— Clinical staging from exam + imaging

— Systemic staging imaging NOT routine for stage I–II asymptomatic disease (no CT/bone scan/PET)

— Stage III or symptomatic stage II → CT chest/abdomen/pelvis + bone scan, or PET-CT

— Baseline labs: CBC, CMP, LFTs (alk phos as bone metastasis screen)

The triage decision tree after triple assessment:

High-risk benign lesions requiring action:

Risk model use (chemoprevention eligibility):

Cancer staging workflow once confirmed:

Step 3 management: Refer to multidisciplinary breast clinic (surgical oncology, medical oncology, radiation oncology, genetic counseling) — questions reward coordinated rather than sequential referrals.

Board pearl: Routine tumor markers (CA 15-3, CA 27.29, CEA) are not used for screening or initial staging — only sometimes for monitoring metastatic disease response.

Pharmacotherapy — Chemoprevention and Adjuvant Therapy Overview

— Tamoxifen 20 mg PO daily × 5 years — SERM; reduces invasive ER+ breast cancer by ~50%. Use in pre- or postmenopausal women ≥35 with 5-year Gail risk ≥1.67%, ADH, ALH, or LCIS.

— Raloxifene 60 mg PO daily — postmenopausal only; slightly less effective than tamoxifen but fewer endometrial cancers and thromboembolic events.

— Aromatase inhibitors (anastrozole, exemestane) — postmenopausal only; off-label but supported by USPSTF.

— Increased risk: endometrial cancer, DVT/PE, stroke, cataracts, hot flashes

— Investigate any postmenopausal bleeding on tamoxifen with endometrial biopsy

— Avoid concurrent strong CYP2D6 inhibitors (paroxetine, fluoxetine, bupropion) — reduces conversion to active endoxifen; use venlafaxine or escitalopram for hot flashes instead

— Premenopausal: tamoxifen × 5–10 years ± ovarian suppression (GnRH agonist) for higher-risk cases

— Postmenopausal: aromatase inhibitor × 5 years, or sequence with tamoxifen

— Trastuzumab ± pertuzumab × 1 year for HER2+ disease; monitor LVEF every 3 months (cardiotoxicity)

— Use Oncotype DX recurrence score — high score (≥26) → benefit from chemotherapy; low score → endocrine therapy alone

— Adjuvant zoledronic acid reduces bone recurrence in postmenopausal women; standard for AI-induced bone loss with T-score < -2.0

Chemoprevention for high-risk women (no cancer diagnosis):

Tamoxifen adverse effects to counsel:

Adjuvant endocrine therapy (ER+ cancer, post-curative-intent surgery):

HER2-targeted therapy:

Chemotherapy decision (ER+/HER2-/node-negative):

Bisphosphonate / denosumab:

Step 3 management: Before starting an aromatase inhibitor, get a baseline DEXA; monitor every 1–2 years; supplement calcium 1200 mg + vitamin D 800–1000 IU.

Board pearl: Switch a patient on paroxetine for hot flashes to venlafaxine if she starts tamoxifen — a classic Step 3 drug-interaction question.

Procedural and Surgical Management

— Breast-conserving therapy (BCT) = lumpectomy + whole-breast radiation — equivalent survival to mastectomy for appropriately selected tumors (typically <5 cm, single focus, achievable negative margins, no diffuse calcifications, not pregnant in 1st/2nd trimester)

— Total (simple) mastectomy — preferred for multicentric disease, large tumor relative to breast size, inability to receive radiation, BRCA carriers (often bilateral), patient preference

— Nipple- or skin-sparing mastectomy with immediate reconstruction — cosmetically preferred when oncologically safe

— Sentinel lymph node biopsy (SLNB) — standard for clinically node-negative disease; uses radiocolloid + blue dye

— Axillary lymph node dissection (ALND) — reserved for clinically positive nodes, ≥3 positive sentinel nodes, or after neoadjuvant chemo with residual disease (selective)

— Z0011 trial principle: In T1–T2 clinically node-negative women undergoing BCT with whole-breast radiation, 1–2 positive sentinel nodes do not require completion ALND

— Inflammatory breast cancer (always)

— Locally advanced / inoperable disease (downstage to operable)

— HER2+ or triple-negative tumors >2 cm or node-positive (pathologic complete response is prognostic)

— Desire to convert mastectomy candidate to BCT candidate

— Whole-breast RT after lumpectomy — standard 3–6 weeks; hypofractionated regimens now preferred

— Post-mastectomy RT for tumors >5 cm, ≥4 positive nodes, or positive margins

— Cyst aspiration for symptomatic simple cysts

— Image-guided vacuum-assisted excision for some high-risk lesions

— Excision of fibroadenomas only if >2–3 cm, growing, or symptomatic

Surgical options for confirmed invasive breast cancer:

Axillary management:

Neoadjuvant therapy indications:

Radiation therapy:

Procedures for benign disease:

CCS pearl: Sequence orders as biopsy → multidisciplinary discussion → surgery + SLNB → adjuvant therapy — jumping straight to mastectomy without tissue diagnosis loses points.

Board pearl: Inflammatory breast cancer never gets upfront surgery — always neoadjuvant chemotherapy first, then modified radical mastectomy, then radiation.

Special Populations — Elderly and Renal/Hepatic Impairment

— Breast cancer incidence peaks in 70s; competing comorbidities drive aggressiveness of workup

— Continue diagnostic imaging and biopsy for palpable masses regardless of age if life expectancy >5–10 years

— Screening mammography evidence weakens after age 75; USPSTF gives I (insufficient) statement >75 — shared decision based on health and life expectancy

— CALGB 9343 trial: Women ≥70 with T1, ER+, node-negative tumors undergoing lumpectomy + tamoxifen had no survival benefit from adjuvant radiation — RT can be omitted in this group

— SLNB may be omitted in clinically node-negative ER+ tumors in elderly when results won't change management

— Use Comprehensive Geriatric Assessment (CGA) or G8 screening before chemotherapy in patients ≥70

— Frailty predicts chemotherapy toxicity better than chronologic age

— Gadolinium-based MRI contrast: avoid group 1 agents if eGFR <30 (nephrogenic systemic fibrosis); group 2 agents (macrocyclic) acceptable with caution

— Iodinated contrast for CT staging: hydration protocol, hold metformin in select cases

— Chemotherapy dose adjustments: capecitabine reduce if CrCl <50; cisplatin avoid if CrCl <60; methotrexate cleared renally

— Bisphosphonates (zoledronic acid) contraindicated if CrCl <30–35; use denosumab instead (but monitor calcium closely)

— Tamoxifen is hepatically metabolized — monitor LFTs; rare hepatotoxicity

— Aromatase inhibitors — dose adjustments in severe hepatic impairment

— Doxorubicin and paclitaxel require dose reduction with elevated bilirubin

— Calcium 1200 mg + vitamin D 800–1000 IU daily, weight-bearing exercise, DEXA q1–2 years, bisphosphonate or denosumab if osteoporotic

Older adults (≥70):

Functional status assessment:

Renal impairment:

Hepatic impairment:

Bone health on AI:

Step 3 management: In an 82-year-old with multiple comorbidities and a small ER+ tumor, lumpectomy + tamoxifen alone (skip RT and possibly SLNB) is appropriate — quality of life takes precedence over aggressive locoregional control.

Board pearl: "Old enough not to get radiation" = ≥70 + T1 + ER+ + node-negative + BCT planned.

Special Populations — Pregnancy, Lactation, and Young Patients

— Diagnosed during pregnancy or within 1 year postpartum; ~1 in 3,000 pregnancies

— Often presents at more advanced stage due to diagnostic delay from "breast changes attributed to pregnancy"

— Any persistent mass >2 weeks in a pregnant patient must be imaged — ultrasound first, mammography is safe with shielding

— Core needle biopsy is safe in pregnancy

— Surgery safe in all trimesters; modified radical mastectomy historically preferred, but BCT possible with RT deferred to postpartum

— Chemotherapy (anthracycline/cyclophosphamide ± taxane) safe in 2nd and 3rd trimesters; avoid in 1st trimester (teratogenic)

— Contraindicated in pregnancy: tamoxifen, aromatase inhibitors, trastuzumab (oligohydramnios, fetal renal impairment), radiation therapy, methotrexate

— Avoid pregnancy termination as a routine recommendation — outcomes are equivalent if treated appropriately

— Breast mass during lactation is most commonly galactocele, mastitis, or abscess

— Persistent mass after antibiotic treatment of mastitis (1–2 weeks) → US and biopsy

— Breastfeeding can usually continue on the unaffected side during workup and most treatments (stop during chemotherapy)

— Most are fibroadenomas; characteristic on US (oval, parallel orientation, circumscribed, hypoechoic)

— Cystosarcoma phyllodes: rapidly growing fibroadenoma-like mass in 30s–40s — needs wide local excision (1-cm margins)

— Cancer in young women tends toward higher-grade, triple-negative, HER2+ phenotypes and worse prognosis stage-for-stage

— Most palpable masses are normal breast bud, fibroadenoma, or juvenile fibroadenoma — observe, avoid biopsy of breast bud (can cause amastia)

Pregnancy-associated breast cancer (PABC):

Treatment principles during pregnancy:

Lactation:

Young women (<40) with breast mass:

Pediatric/adolescent:

Board pearl: In a 22-year-old with a 1.5-cm smooth mobile mass, US showing classic fibroadenoma, and clinical correlation — observation with repeat exam/US in 6 months is appropriate; biopsy only if growing, >2–3 cm, or symptomatic.

Step 3 management: Refer pregnancy-associated cancer to a high-risk MFM + oncology team early; coordinate delivery timing with chemotherapy cycles (avoid delivery within 3 weeks of last cycle to prevent neonatal cytopenias).

Complications and Adverse Outcomes

— Metastatic spread — bone (most common), liver, lung, brain

— Hypercalcemia of malignancy — bone metastases or PTHrP-mediated; presents with confusion, polyuria, constipation

— Spinal cord compression — back pain + neurologic deficit; emergency MRI + dexamethasone + radiation/surgery

— Pleural effusion / lymphangitic carcinomatosis — dyspnea

— Pathologic fracture — femoral neck lesion >2.5 cm or with >50% cortical involvement is prophylactically fixed

— Lymphedema after ALND (5–40%) — lifelong arm precautions, early PT referral, compression garments

— Seroma, hematoma, wound infection

— Axillary web syndrome ("cording") — palpable cords causing restricted ROM; PT-responsive

— Loss of nipple sensation / cosmetic dissatisfaction

— Acute: dermatitis, fatigue

— Late: rib fractures, brachial plexopathy, radiation pneumonitis (cough/dyspnea 1–6 months later), cardiac toxicity (left-sided RT), secondary malignancies including angiosarcoma of the breast

— Tamoxifen: endometrial cancer, VTE, stroke, hot flashes, cataracts

— Aromatase inhibitors: arthralgias, osteoporosis, hyperlipidemia, vaginal dryness

— Anthracyclines (doxorubicin): cardiomyopathy — baseline + serial LVEF

— Trastuzumab: reversible cardiotoxicity — LVEF q3 months; hold if drop >16% or below 50%

— Taxanes: peripheral neuropathy, hypersensitivity, alopecia

— Cyclophosphamide: hemorrhagic cystitis, secondary leukemias

— CDK4/6 inhibitors (palbociclib, ribociclib, abemaciclib): neutropenia (palbociclib), QT prolongation (ribociclib), diarrhea (abemaciclib)

— Depression, anxiety, body image distress, sexual dysfunction, financial toxicity

— 20–40% experience significant depressive symptoms — screen at each follow-up

Complications of the disease itself:

Surgical complications:

Radiation toxicity:

Endocrine therapy toxicity:

Chemotherapy toxicities:

Psychosocial:

Board pearl: New back pain in a breast cancer survivor = MRI of the entire spine, not just localized films — metastases are often multifocal and missed on plain radiographs.

When to Escalate Care — Specialist Referral and Inpatient Triage

— Any BI-RADS 4 or 5 imaging → breast surgeon or breast imaging clinic within 1–2 weeks for biopsy

— Confirmed cancer → multidisciplinary breast clinic within 2 weeks

— Inflammatory breast cancer suspected → immediate (within days) referral; do not delay for antibiotic trial >7–10 days

— Suspected hereditary syndrome → genetic counselor before testing

— Breast cancer at age ≤50

— Triple-negative at age ≤60

— Male breast cancer

— Bilateral breast cancer

— ≥2 primary breast cancers

— Ashkenazi Jewish ancestry with breast/ovarian/pancreatic/prostate cancer

— ≥3 relatives with breast/ovarian/pancreatic/prostate cancer

— Known family BRCA1/2 or other high-penetrance variant

— Febrile neutropenia (ANC <500, T ≥38.3 once or ≥38.0 sustained 1 hour) — admit, blood cultures, broad-spectrum antibiotics within 1 hour (cefepime or piperacillin-tazobactam)

— Suspected spinal cord compression — admit, MRI, dexamethasone 10 mg IV bolus then 4 mg q6h, radiation oncology + neurosurgery consult

— Hypercalcemic crisis (Ca >14 or symptomatic) — admit for IV saline + bisphosphonate/denosumab + calcitonin

— Brain metastases with edema/herniation risk — admit, dexamethasone, neurosurgery/RO consult

— Severe chemotherapy toxicity: intractable nausea/vomiting, severe diarrhea with dehydration, sepsis

— New back pain → urgent imaging

— New dyspnea → CT-PA (PE common in cancer) or evaluate for pleural effusion

— Persistent unexplained weight loss → restaging

Urgent specialist referral indications:

Genetic counseling referral criteria (NCCN abbreviated):

Inpatient triage triggers:

Outpatient escalation:

CCS pearl: For febrile neutropenia, the clock starts at the door — orders should read: blood cultures × 2, CBC with diff, CMP, lactate, UA, CXR, then empirical antibiotic within 60 minutes. Delay loses points.

Step 3 management: Establish patient-reported outcome check-ins (phone or portal) at 1 week post-chemo to catch toxicity early; this aligns with value-based oncology care models.

Key Differentials — Benign Breast Lesions

— Most common solid benign mass; ages 15–35

— Smooth, mobile, rubbery, "breast mouse"

— US: oval, parallel, circumscribed, hypoechoic

— Management: observe if classic and <2 cm; excise if growing or symptomatic

— Ages 35–50, hormonally driven

— Soft, mobile, may be tender, can fluctuate with cycle

— US: anechoic with posterior enhancement

— Management: aspirate if symptomatic; otherwise observe

— Most common cause of "lumpy" breasts in premenopausal women

— Bilateral, diffuse nodularity, cyclic tenderness

— Not a discrete mass; reassure

— History of trauma, surgery, or radiation

— Firm, irregular, may have skin tethering → mimics cancer

— Mammogram: oil cyst with rim calcifications (pathognomonic)

— Biopsy if imaging not classic

— Lactating women; milk-filled cyst

— Aspirate diagnostic and therapeutic

— Painful, erythematous, warm; fever, flu-like symptoms

— Continue breastfeeding; dicloxacillin or cephalexin; MRSA coverage (TMP-SMX, clindamycin) if risk factors

— Abscess → US-guided aspiration ± I&D; do not stop breastfeeding

— Solitary, subareolar; presents with unilateral, single-duct, bloody nipple discharge

— Workup: ductogram or MRI; excision recommended (5% upgrade to malignancy)

— Rapidly growing, fibroadenoma-like, ages 30–50

— Spectrum: benign → borderline → malignant

— Wide local excision with 1-cm margins; SLNB not indicated (hematogenous spread if malignant)

— Superficial thrombophlebitis of breast veins; palpable cord; self-limited; NSAIDs

Fibroadenoma:

Simple cyst:

Fibrocystic change:

Fat necrosis:

Galactocele:

Lactational mastitis / abscess:

Intraductal papilloma:

Phyllodes tumor:

Mondor disease:

Key distinction: Fibroadenoma is soft, mobile, painless in a young woman; cancer is hard, fixed, painless in an older woman. Both are painless — pain alone does NOT exclude malignancy.

Board pearl: A "rapidly growing fibroadenoma" in a 40-year-old is phyllodes until proven otherwise — needs excision, not observation.

Key Differentials — Skin, Nipple, and Other Mimics

— Unilateral, eczematous, scaly, erythematous nipple-areolar lesion that does not resolve with topical steroids

— Associated underlying DCIS or invasive cancer in >90% of cases

— Punch biopsy of the nipple is diagnostic — Paget cells in epidermis

— Key distinction from eczema: Paget starts at the nipple and spreads to areola; eczema starts on the areola, often bilateral, responds to topical steroids

— Rapid-onset (<6 months) diffuse erythema involving >1/3 of breast, peau d'orange, warmth, often no discrete mass

— Pathognomonic: dermal lymphatic invasion on skin punch biopsy

— Misdiagnosed as mastitis — non-lactating women with "mastitis" need biopsy, not just antibiotics

— Mastitis: lactating, focal, responds to antibiotics within 48–72 hours

— Inflammatory cancer: non-lactating (usually), diffuse, no response to antibiotics, peau d'orange

— Any "mastitis" failing 1–2 weeks of antibiotics → biopsy

— Concentric, rubbery, subareolar mass — distinguish from male breast cancer (eccentric, hard, fixed, with skin/nipple change)

— Causes: physiologic (puberty, elderly), drugs (spironolactone, cimetidine, ketoconazole, anabolic steroids, antipsychotics), liver disease, hyperthyroidism, testicular tumors

— Workup: TFTs, LFTs, β-hCG, testosterone, estradiol, LH

— Pathologic (worrisome): unilateral, single-duct, spontaneous, bloody/serous-bloody, persistent → imaging + duct excision

— Physiologic: bilateral, multi-duct, expressed only, milky/green/yellow → reassure; check prolactin + TSH if milky in non-lactating

— Costochondritis (Tietze), trauma, herpes zoster prodrome

— Reproducible tenderness on palpation of costochondral junction; no mass

Paget disease of the nipple:

Inflammatory breast cancer:

Bacterial mastitis vs. inflammatory cancer:

Gynecomastia (men):

Nipple discharge differential:

Chest wall pain mimicking breast disease:

Step 3 management: A man with eccentric, hard, fixed retroareolar mass and ipsilateral axillary adenopathy → diagnostic mammogram + US + core biopsy. Male breast cancer is almost always ER+ and warrants BRCA2 testing.

Board pearl: Eczematous nipple lesion + failed topical steroids = punch biopsy of the nipple, not another cream.

Secondary Prevention and Long-Term Plan

— Treatment summary, surveillance schedule, late effects watch list, lifestyle recommendations

— Designate PCP vs. oncologist responsibility for each surveillance element

— History and physical: every 3–6 months for years 1–3, every 6–12 months for years 4–5, annually thereafter

— Mammography: annual; first post-treatment mammogram 6–12 months after RT to the treated breast

— MRI: annual if lifetime risk ≥20% (BRCA carriers, chest XRT history)

— Pelvic exam: annually if on tamoxifen; investigate any abnormal uterine bleeding

— Bone density: baseline + every 1–2 years on AI or ovarian suppression

— No routine CBC, LFTs, tumor markers, CT, bone scan, or PET in asymptomatic patients

— 5–10 years tamoxifen or AI; adherence drops to ~50% by year 5

— Counsel on managing side effects: vaginal moisturizers, SSRIs/SNRIs (not paroxetine with tamoxifen) for hot flashes, exercise for arthralgias, weight loss

— Limit alcohol to <1 drink/day (every drink raises risk ~7–10%)

— Maintain healthy BMI — postmenopausal obesity raises recurrence and primary risk

— Physical activity ≥150 min/week moderate or 75 min vigorous

— Avoid combined HRT; if needed for severe menopausal symptoms in a non-cancer patient, limit duration

— Breastfeeding lowers risk

— Influenza annually, COVID per CDC, pneumococcal per age/risk, Shingrix at age ≥50 (including immunocompromised on chemotherapy after recovery)

— Avoid live vaccines during chemotherapy

— Tamoxifen/raloxifene/AI × 5 years for high-risk women without cancer (Gail ≥1.67%, ADH, ALH, LCIS)

Survivorship care plan (handed to patient and PCP after active treatment):

Surveillance schedule for breast cancer survivors:

Endocrine therapy adherence:

Lifestyle modification (evidence-based risk reduction):

Vaccinations:

Chemoprevention reminder:

Step 3 management: Coordinate shared follow-up — oncologist handles disease-specific surveillance; PCP manages bone health, cardiovascular risk (anthracycline/HER2 survivors), lipid/diabetes screening, mood, and second primary cancer screening (colon, cervical, skin).

Board pearl: Asymptomatic post-treatment surveillance does NOT include routine PET/CT, tumor markers, or chest imaging — choosing those answers is a trap.

Follow-Up, Monitoring, and Counseling

— Probably benign (BI-RADS 3): imaging at 6, 12, and 24 months to document stability before returning to routine screening

— Aspirated simple cyst with complete resolution: clinical follow-up in 4–6 weeks; if recurs, US and biopsy

— Fibroadenoma observed: clinical exam + US at 6 and 12 months; if stable for 2 years, may return to age-appropriate screening

— Excision confirms pathology

— Enroll in high-risk surveillance: clinical exam every 6 months, annual mammogram + MRI (if lifetime risk ≥20%), discuss chemoprevention

— Arm care after ALND/SLNB: avoid blood draws, BP cuffs, IV insertion on ipsilateral arm; promptly treat any infection

— Reconstruction options: implant-based, autologous (DIEP, TRAM); timing immediate vs. delayed

— Fertility preservation: refer before chemotherapy if of reproductive age — oocyte/embryo cryopreservation, ovarian suppression with GnRH agonist during chemotherapy

— Contraception during/after treatment: non-hormonal preferred (copper IUD, barrier); pregnancy generally deferred 2–3 years

— Anthracycline + trastuzumab survivors → baseline echo, every 3 months during trastuzumab, then periodically; lifelong cardiac risk factor management

— DEXA baseline + every 1–2 years

— Treat with bisphosphonate or denosumab if T-score < -2.0 or fracture

— PHQ-9 / GAD-7 at follow-up visits; up to 40% of survivors have depression/anxiety

— Refer to psycho-oncology, support groups (e.g., Susan G. Komen, Living Beyond Breast Cancer)

— New persistent bone pain, headache, vision changes, dyspnea, abdominal pain, jaundice, unexplained weight loss, new breast/chest wall mass — call same week

Benign mass follow-up cadence:

Atypia / high-risk lesion follow-up:

Post-cancer treatment counseling:

Cardiotoxicity surveillance:

Bone health on AI / ovarian suppression:

Mental health screening:

Symptom red flags to teach patient:

Step 3 management: At every follow-up, document a 5-item checklist: disease surveillance, treatment side effects, bone/cardiac/mental health, lifestyle, and adherence. Missing one is a common Step 3 quality-of-care answer choice.

Board pearl: Tamoxifen + new vaginal bleeding → endometrial biopsy, not TVUS (TVUS unreliable in tamoxifen users due to subendothelial cystic changes).

Ethical, Legal, and Patient Safety Considerations

— Discuss purpose, risks (bleeding, infection, scarring, false-negative), alternatives, and what happens with each possible result

— Explicitly cover risk of upgrade when ADH or papilloma is found on core biopsy → patient must consent in advance to potential surgical excision

— Implications for the patient (risk-reducing surgery, surveillance, chemoprevention)

— Implications for family members (cascade testing)

— Insurance and discrimination: GINA protects health insurance and employment but not life, disability, or long-term care insurance — must disclose

— Possibility of variants of uncertain significance (VUS) — do not act on VUS alone

— BRCA testing generally deferred until age 18 (or until clinical interventions become available, typically age 25 for breast surveillance) — autonomy and psychological burden considerations

— Incidental contralateral abnormality on staging imaging → disclose, work up appropriately

— Elderly patient with dementia found to have breast mass: assess capacity for this specific decision; if lacking, involve healthcare proxy; consider goals-of-care discussion before aggressive workup

— Biopsy result communication: never deliver a cancer diagnosis by voicemail or portal alone; arrange in-person or scheduled phone visit

— Post-discharge after surgery: ensure 24–48 hour follow-up call, drain care education, pathology disclosure plan

— Hand-off from oncologist back to PCP: requires survivorship care plan document

— Wrong-side surgery — preoperative marking, time-out, verification

— Specimen mix-up — labeling protocols at biopsy

— Delayed diagnosis from "negative mammogram" complacency — re-image and biopsy palpable masses regardless of recent screening

— Not typically applicable; however, suspicion of abuse explaining "trauma-related" breast injuries warrants screening and reporting per state law

Informed consent for biopsy/surgery:

Genetic testing — informed consent elements:

Adolescents and genetic testing:

Disclosure of unexpected findings:

Decision-making capacity and surrogate consent:

Transitions of care — high-risk handoff points:

Patient safety / never events:

Mandatory reporting:

Step 3 management: When a patient declines biopsy of a BI-RADS 5 lesion, document informed refusal with explicit discussion of natural history, prognosis without treatment, and offer of second opinion — and schedule re-engagement, do not simply discharge from care.

Board pearl: GINA does NOT cover life or disability insurance — counsel patients to consider these before genetic testing.

High-Yield Associations and Rapid-Fire Facts

— Most cancers in upper outer quadrant (largest tissue volume + tail of Spence)

— Primary lymphatic drainage to axillary nodes; medial tumors may drain to internal mammary nodes

— BRCA1: chromosome 17; triple-negative tumors; ovarian (40%), breast (60–70%) lifetime risk

— BRCA2: chromosome 13; ER+ tumors; male breast cancer, pancreatic, prostate cancer association

— Li-Fraumeni (TP53): sarcomas, breast, brain, adrenocortical, leukemia

— Cowden (PTEN): breast, thyroid, endometrial; macrocephaly, hamartomas

— CDH1: lobular breast cancer + diffuse gastric cancer

— PALB2: breast cancer risk approaching BRCA2

— Invasive ductal carcinoma: most common (75%)

— Invasive lobular: "Indian-file" cells, often bilateral/multifocal, hard to detect on mammogram and exam

— DCIS: confined to ducts; calcifications on mammogram; treat with lumpectomy + RT or mastectomy; no SLNB unless mastectomy

— LCIS: marker of bilateral risk, not a precursor lesion — surveillance + chemoprevention

— Triple-negative: ER-/PR-/HER2-; aggressive; young/Black/BRCA1 associations; chemotherapy is mainstay

— HER2+: trastuzumab transformed prognosis from worst to favorable

— Tamoxifen + paroxetine = bad combo (CYP2D6 inhibition)

— Trastuzumab = cardiomyopathy (reversible); doxorubicin = cardiomyopathy (irreversible)

— Aromatase inhibitors → osteoporosis + arthralgias

— Anastrozole, letrozole (non-steroidal); exemestane (steroidal)

— USPSTF (2024): biennial mammography ages 40–74 (Grade B)

— ACS: annual ages 45–54, biennial 55+

— High-risk (lifetime ≥20%): annual MRI + mammogram starting age 25–30 (or 10 years before earliest family case)

— 1 in 8 US women lifetime breast cancer risk

— 5-year survival localized 99%, regional 86%, distant 30%

— Sentinel node identification rate >95% with combined dye + radiocolloid

Anatomy/lymphatic drainage:

Genetics rapid-fire:

Pathology pearls:

Drug-specific pearls:

Screening recap:

Numbers to remember:

Board pearl: "Peau d'orange + diffuse erythema + non-lactating" = inflammatory breast cancer until proven otherwise — skin punch biopsy, not antibiotics.

Board Question Stem Patterns

— 22-year-old, 1.5-cm smooth mobile non-tender mass, no family history

— Answer: Ultrasound first; if classic fibroadenoma features and clinical correlation, observation with repeat US in 6 months

— 38-year-old, palpable firm mass; "her screening mammogram 9 months ago was normal"

— Answer: Diagnostic mammogram + targeted US (regardless of recent screening) → core needle biopsy

— 64-year-old, new 2-cm hard non-tender mass with skin dimpling

— Answer: Diagnostic mammogram + US + core needle biopsy; expect ER+/HER2- invasive ductal carcinoma

— 52-year-old non-lactating woman with 3 weeks of breast erythema, no fever, completed 14 days of cephalexin without improvement

— Answer: Skin punch biopsy + diagnostic imaging; suspect inflammatory breast cancer

— 58-year-old with unilateral scaly nipple lesion not responding to topical steroids

— Answer: Punch biopsy of nipple → Paget disease; workup underlying DCIS/invasive cancer

— 45-year-old, single-duct bloody discharge, no palpable mass, normal mammogram

— Answer: Ductogram or MRI → likely intraductal papilloma → duct excision

— 32-year-old with mother and maternal aunt with premenopausal breast cancer, Ashkenazi Jewish

— Answer: Genetic counseling + BRCA1/2 testing; if positive, MRI surveillance starting age 25, discuss risk-reducing options

— Core biopsy returns "atypical ductal hyperplasia"

— Answer: Surgical excisional biopsy (15–20% upgrade rate); discuss chemoprevention afterward

— Patient on tamoxifen has hot flashes; physician considers SSRI

— Answer: Use venlafaxine or escitalopram, avoid paroxetine/fluoxetine (CYP2D6 inhibitors)

— Postmenopausal patient on tamoxifen with new vaginal spotting

— Answer: Endometrial biopsy (not TVUS first)

— 78-year-old with 1.2-cm ER+ node-negative tumor planned for lumpectomy

— Answer: Lumpectomy + tamoxifen/AI; may omit radiation (CALGB 9343)

Classic stem 1 — Young woman, smooth mass:

Classic stem 2 — Premenopausal woman, ≥30, palpable mass:

Classic stem 3 — Postmenopausal woman, new mass:

Classic stem 4 — Failed mastitis:

Classic stem 5 — Eczematous nipple:

Classic stem 6 — Bloody unilateral discharge:

Classic stem 7 — Family history red flag:

Classic stem 8 — High-risk lesion on biopsy:

Classic stem 9 — Drug interaction trap:

Classic stem 10 — Tamoxifen + bleeding:

Classic stem 11 — Elderly with small ER+ tumor:

Board pearl: When a stem mentions "the mammogram is normal" alongside a palpable mass, the right answer is still biopsy — do not be reassured.

One-Line Recap

Every persistent, discrete breast mass — regardless of age, prior imaging, or pain status — requires structured triple assessment (clinical exam, age-appropriate imaging, and tissue sampling when indicated), because clinically suspicious masses can be mammographically occult and benign-feeling masses can be malignant.

— <30: ultrasound first

— ≥30: diagnostic mammogram + ultrasound

— Pregnant/lactating: ultrasound first

— MRI is not the initial test for a palpable mass

— Image-guided core needle biopsy is the standard for solid masses (provides histology + receptor status)

— Triple test concordance required to defer biopsy

— ADH, papilloma, radial scar, flat epithelial atypia → surgical excision (upgrade risk)

— Hard, fixed, irregular non-tender mass

— Skin dimpling, peau d'orange, nipple retraction, eczematous nipple

— Unilateral, single-duct, spontaneous bloody discharge

— "Mastitis" failing 1–2 weeks of antibiotics — especially non-lactating

— Any palpable mass in a postmenopausal woman

— Refer high-risk patients to genetic counseling before testing

— Chemoprevention (tamoxifen/raloxifene/AI) for women with Gail 5-year risk ≥1.67%, ADH, ALH, or LCIS

— Coordinate multidisciplinary care for confirmed cancer

— Surveillance after treatment is clinical + annual mammography only — no routine tumor markers, CT, PET, or bone scan in asymptomatic survivors

— Switch paroxetine to venlafaxine if starting tamoxifen

— Investigate new vaginal bleeding on tamoxifen with endometrial biopsy

Imaging by age:

Tissue is the issue:

Red flags that mandate biopsy regardless of imaging:

Step 3 management essentials:

Board-saving mantra: A normal mammogram does not rule out cancer in a palpable mass — biopsy still wins.