Male Breast Imaging

Male Breast A&P - Not Just Gals!

• Rudimentary Structure: Skin, nipple-areola, subcutaneous fat, basic ductal system within stroma.
• Ductal System:
  • Few, small, branching ducts converging at nipple.
  • Lined by inner epithelial & outer myoepithelial cells.
• Lobules: Generally absent/rudimentary; no acini due to low estrogen/progesterone.
• Stroma: Mainly fibrous connective tissue, some adipose.
• Hormonal Balance: Testosterone inhibits; estrogen (even low levels) can stimulate ducts.

⭐ Male breast lacks significant lobular development, primarily consisting of ducts and stroma. This is key for pathology.

Benign Male Lumps - Mostly Harmless

⭐ Gynecomastia is the most common benign condition of the male breast.

• Gynecomastia: Proliferation of glandular & stromal elements.
  • Causes: Hormonal imbalance (↑estrogen/androgen ratio), drugs (📌 Spironolactone, Cimetidine, Alcohol, Digoxin - SCAD), systemic diseases (liver, renal, hyperthyroidism), idiopathic.
  • Patterns:

    Pattern	MG Features	US Features	Chronicity
    Nodular	Flame-shaped/nodular retroareolar	Hypoechoic retroareolar nodule	<1 yr
    Dendritic	Finger-like projections	Heterogeneous, prominent ducts	Variable
    Diffuse Glandular	Female-like, heterogeneous density	Diffuse glandular proliferation	>1 yr

• Pseudogynecomastia: Fat deposition, no glandular tissue. MG: Radiolucent. US: ↑Subcutaneous fat.
• Other Benign: Lipoma (radiolucent, encapsulated fat), sebaceous cyst (well-defined, superficial, dermal), hematoma (post-trauma), abscess (inflammatory signs).

Male Breast Cancer - Rare But Real

• Accounts for < 1% of all breast cancers; incidence is ↑.
• Presents later than in females (mean age: 60-70 years).

Risk Factors:

Clinical Presentation:

• Painless, firm, subareolar lump (often eccentric).
• Nipple changes: retraction, discharge (bloody), ulceration.
• Axillary lymphadenopathy.

Imaging:

• Mammography: Eccentric, retroareolar, spiculated mass. Calcifications less common than in females.
• Ultrasound: Hypoechoic, irregular, spiculated mass; posterior acoustic shadowing. Doppler shows vascularity.

Histology:

⭐ Invasive Ductal Carcinoma (IDC), No Special Type, is the most common histological type (> 85%), similar to females. Ductal Carcinoma In Situ (DCIS) is also seen.

• Lobular carcinoma is rare (due to rudimentary lobules in males).

Imaging Male Breasts - Spotting Trouble

• Key Modalities: Mammography (MMG) & Ultrasound (USG).

  • MMG: Standard CC & MLO views. Adjust for male anatomy (smaller paddle, ensure pectoralis visualization).
  • USG: Differentiates cystic/solid; characterizes masses; guides biopsy.

• Benign vs. Malignant Features:

  Feature	Benign (e.g., Gynecomastia)	Malignant (e.g., Invasive Ductal Carcinoma)
  MMG Mass	Diffuse, flame-shaped, nodular	Irregular, spiculated mass
  Margins	Circumscribed, indistinct	Spiculated, ill-defined
  Calcifications	Coarse, benign-appearing	Pleomorphic, fine linear microcalcifications
  USG Mass	Oval, wider-than-tall, circumscribed	Irregular, taller-than-wide, spiculated
  Echotexture	Variable, often hypoechoic (glandular)	Marked hypoechogenicity, heterogeneous
  Location	Typically subareolar	Often subareolar, may be eccentric

⭐ Most male breast cancers occur in the subareolar region due to the concentration of ductal tissue there.

• BI-RADS Assessment & Management Flowchart:

High‑Yield Points - ⚡ Biggest Takeaways

• Gynecomastia, most common, is typically bilateral, retroareolar; US differentiates it from cancer.
• Male breast cancer: rare (<1%), usually Invasive Ductal Carcinoma (IDC), often presents late.
• Risk factors: BRCA2 mutations, Klinefelter's, family history, obesity, advanced age, liver disease.
• Mammography (CC & MLO views) & Ultrasound are key for diagnosis and characterization.
• Cancer signs: eccentric, spiculated mass, suspicious microcalcifications, skin/nipple retraction, axillary nodes.
• Biopsy for BI-RADS 4/5 lesions; typical gynecomastia is BI-RADS 2 (benign).