Mass in Male (Gynecomastia, Cancer)

Abstract Gynecomastia is a benign condition manifesting as enlarged breasts in men and boys. This increased breast tissue is caused by excess fibroglandular deposits and is caused by hormonal imbalances, commonly due to estrogen excess or from various drugs, such as spironolactone, ketoconazole, cimetidine, ranitidine, and specific HIV therapies. Patients generally present with bilateral subareolar enlarged breasts (however, unilateral gynecomastia also occurs), which commonly exhibit tenderness on palpation, swelling, palpable lumps, or nipple discharge. This chapter reviews the important imaging protocols, pitfalls, differential diagnoses, radiology–pathology correlation, and management recommendations for gynecomastia and cancer of the male breast. Topics discussed include gynecomastia, breast cancer, pseudogynecomastia, hypogonadism, and lymphangioma.