Patient 1 – A 26-year-old woman presents to her primary care physician for an annual exam. She currently does not have any acute concerns and says her health has been generally well. Medical history is significant for asthma, which is managed with an albuterol inhaler. Her last pap smear was unremarkable. She is currently sexually active with one male and consistently uses condoms. She occasionally smokes marijuana and drinks wine once per week. Her mother recently passed away from advanced ovarian cancer. Her sister is 37-years-old and was recently diagnosed with breast cancer and ovarian cancer. Physical examination is remarkable for a mildly anxious woman. Patient 2 – A 27-year-old woman presents to her primary care physician for an annual exam. She says that she would like to be screened for breast cancer since two of her close friends were recently diagnosed. She noticed she has a small and mobile mass on her left breast, which increases in size and becomes tender around her time of menses. Family history is remarkable for hypertension in the father. The physical exam is significant for a small, well-defined, and mobile mass on her left breast that is not tender to palpation. Which of the following is the best next step in management for patient 1 and 2?

Patient 1 – BRCA testing. Patient 2 – Breast ultrasound

Patient 1 – Breast ultrasound. Patient 2 – Return in 3 months for a clinical breast exam

Patient 1 – Reassurance. Patient 2 – Breast ultrasound

Patient 1 – CA-125 testing. Patient 2 – BRCA testing

Patient 1 – Breast and ovarian ultrasound. Patient 2 – Mammography

A 40-year-old man presents with a painless firm mass in the right breast. Examination shows retraction of the nipple and the skin is fixed to the underlying mass. The axillary nodes are palpable. Which of the following statements is FALSE regarding the above condition?

Lobular cancer is the most common breast cancer in males

BRCA2 mutations are associated with increased risk

These are positive for estrogen receptor

Endocrine therapy plays an important role in treatment

Gynecomastia may be caused by certain medications

A 29-year-old nulligravid woman comes to the physician because of a 10-day history of small quantities of intermittent, blood-tinged discharge from her left nipple. There is no personal or family history of serious illness. She has smoked 1 pack of cigarettes daily for 5 years. Her last menstrual period was 12 days ago. She is sexually active and uses condoms inconsistently. Physical examination shows scant serosanguinous fluid expressible from the left nipple. There is no palpable breast mass or axillary lymphadenopathy. Examination shows no other abnormalities. Which of the following is the most appropriate next step in management?

Image-guided core biopsy of the affected duct

A 32-year-old woman presented for her annual physical examination. She mentioned that her family history had changed since her last visit: her mother was recently diagnosed with breast cancer and her sister tested positive for the BRCA2 mutation. The patient, therefore, requested testing as well. If the patient tests positive for the BRCA1 or BRCA2 mutation, which of the following is the best screening approach?

Twice-yearly clinical breast exams, annual mammography, annual breast MRI, and breast self-exams

Order magnetic resonance imaging of the breast

Annual ultrasound, annual mammography, and monthly self-breast exams

Annual clinical breast exams, annual mammography, and monthly self-breast exams

A 47-year-old woman comes to the physician for a mass in her left breast she noticed 2 days ago during breast self-examination. She has hypothyroidism treated with levothyroxine. There is no family history of breast cancer. Examination shows large, moderately ptotic breasts. The mass in her left breast is small (approximately 1 cm x 0.5 cm), firm, mobile, and painless. It is located 4 cm from her nipple-areolar complex at the 7 o'clock position. There are no changes in the skin or nipple, and there is no palpable axillary adenopathy. No masses are palpable in her right breast. A urine pregnancy test is negative. Mammogram showed a soft tissue mass with poorly defined margins. Core needle biopsy confirms a low-grade infiltrating ductal carcinoma. The pathological specimen is positive for estrogen receptors and negative for progesterone and human epidermal growth factor receptor 2 (HER2) receptors. Staging shows no distant metastatic disease. Which of the following is the most appropriate next step in management?

Lumpectomy with sentinel lymph node biopsy, followed by radiation and hormone therapy

Lumpectomy with sentinel lymph node biopsy followed by hormone therapy

Nipple-sparing mastectomy with axillary lymph node dissection followed by hormone therapy

Nipple-sparing mastectomy with axillary lymph node dissection, followed by radiation and hormone therapy

Radical mastectomy followed by hormone therapy

Male breast cancer for USMLE Step 2 CK: High-Yield Surgery Lessons

👨‍⚕️ Pathophysiology - Not Just for Ladies

Core Mechanism: An increased Estrogen to Androgen ratio is the primary driver, stimulating ductal epithelial proliferation.
Histology: Predominantly Invasive Ductal Carcinoma (IDC), >85% of cases.
- Lobular carcinoma is rare due to rudimentary terminal lobules in the male breast.
Genetics: Strong association with BRCA2 mutations (higher risk than BRCA1).

⭐ Over 90% of male breast cancers are Estrogen Receptor (ER) positive. This makes endocrine therapy (e.g., Tamoxifen) a cornerstone of treatment.

Invasive ductal carcinoma in male breast tissue (histology)

👨‍⚕️ Clinical Manifestations - Lumps & Bumps

Male breast cancer: mammography and ultrasound

Primary Sign: A painless, firm, non-tender, and fixed subareolar mass. This is the presenting symptom in >85% of men.
Location: Typically located just beneath the nipple-areolar complex, but can be eccentric.
Associated Signs: Common due to minimal breast tissue.
- Nipple retraction, inversion, or ulceration.
- Bloody or serosanguinous nipple discharge.
- Skin dimpling (peau d'orange), erythema, or fixation to the skin.
Lymphadenopathy: Palpable axillary lymph nodes are a frequent finding, present in up to 50% of patients at initial diagnosis.

⭐ Because of the small amount of male breast tissue, tumors are more likely to invade the nipple-areolar complex, skin, and underlying pectoralis muscle early.

🩺 Diagnosis - Spotting the Suspect

Initial Evaluation: Any palpable, firm, subareolar mass in a male is the most common presentation.
- Assess for nipple retraction, bloody discharge, skin changes (dimpling, ulceration), or axillary lymphadenopathy.
Diagnostic Pathway:

Biopsy:
- Core Needle Biopsy (CNB) is the gold standard. It provides tissue for histology and receptor testing (ER, PR, HER2).
- Fine-Needle Aspiration (FNA) is less preferred due to high inadequacy rates.

⭐ Pearl: Unlike in females, screening mammography is not recommended for asymptomatic men. Diagnosis is prompted by symptoms.

🔪 Management - The Surgical Strike

Primary Surgery: Modified Radical Mastectomy (MRM) is the standard of care. It involves removing the entire breast, nipple-areolar complex, and performing an axillary evaluation.
BCT is Rare: Breast-conserving therapy is seldom used due to small breast volume, which leads to poor cosmesis and high rates of positive margins.
Axillary Staging: Essential for prognosis and guiding adjuvant therapy.

Post-Mastectomy Radiation (PMRT): Indicated for high-risk features: tumor >5 cm, positive margins, or significant nodal disease (≥4 nodes).

⭐ Mastectomy is the rule for men. Unlike in female breast cancer, skin-sparing or nipple-sparing techniques are generally avoided due to the high incidence of central tumor location.

Modified Radical Mastectomy for Male Breast Cancer

⚡ Biggest Takeaways

BRCA2 is the most significant genetic risk factor; Klinefelter syndrome is also high-yield.

Typically presents as a painless, subareolar mass in older men (average age ~70).

Histology is almost always Infiltrating Ductal Carcinoma (IDC).

Most tumors are hormone receptor-positive (ER+/PR+), guiding therapy with tamoxifen.

Standard treatment is mastectomy, not lumpectomy, due to small breast size.

Prognosis is similar to females stage-for-stage but often diagnosed at a later stage.

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