A 66-year-old man is found to have bilateral breast enlargement during a routine office visit. The patient reports no breast pain/discomfort, headaches, or vision abnormalities but has had decreased libido and "low energy" for the past several months. Medical problems include hypertension, hyperlipidemia, and osteoarthritis. The patient takes chlorthalidone, simvastatin, and acetaminophen as needed. He does not use over-the-counter or herbal supplements. The patient drinks 1 or 2 alcoholic beverages during social events and does not use tobacco or illicit drugs. He is married and has several adult children. Family history is notable for breast cancer in a maternal aunt. Vital signs are within normal limits. BMI is 32 kg/m². Examination shows normal body hair distribution and no skin rash. Breast examination reveals 2-cm, round, and firm tissue behind the areolas bilaterally with no overlying skin changes or nipple discharge. There are no enlarged lymph nodes. External genitalia are normal in size and appearance, and no testicular masses are present. The remainder of the physical examination is normal. Laboratory results are as follows: Serum chemistry panel and liver aminotransferases are within normal limits, and serum testosterone level is unchanged on repeat testing. Which of the following is the most likely explanation for this patient's breast abnormality?

Question

Quizplus · Accepted Answer

Explanation: This patient has new-onset, bilateral gynecomastia with otherwise normal examination findings. Gynecomastia is benign glandular proliferation of the male breast tissue and is common in neonates, adolescent boys, and older (especially obese) men. Physiologic gynecomastia in older men is related to an imbalance of estrogen to testosterone due to decreased testicular testosterone production and increased conversion of testosterone to estrogen by aromatase in peripheral (mainly adipose) tissue. Breast examination in physiologic gynecomastia typically shows symmetric, firm enlargement of the breast tissue concentrically under the nipple areolar complex. Initial evaluation should include serum chemistries to exclude hepatic and renal disease. Hormonal studies typically include TSH, serum testosterone, and measurement of estrogen, prolactin, LH, and hCG. Patients with benign examination and biochemical findings can be followed, and many have spontaneous resolution. (Choice A) Breast cancer is an uncommon cause of gynecomastia. Findings to suggest breast carcinoma include unilateral, eccentric enlargement of breast tissue, hard or fixed masses, and associated lymphadenopathy or skin changes. (Choice B) Cirrhosis is a common cause of gynecomastia but is typically associated with other signs of hyperestrogenism, such as spider angiomata, loss of sexual hair, testicular atrophy, and palmar erythema. This patient's light alcohol intake and normal hepatic markers make significant cirrhosis unlikely. (Choice C) Medications are a common, potentially reversible cause of gynecomastia. However, this patient takes no medications associated with gynecomastia (eg, spironolactone, cimetidine, 5-alpha-reductase inhibitors, ketoconazole). (Choice E) Pseudogynecomastia refers to excess fat deposition in the breast rather than glandular enlargement. Pseudogynecomastia typically causes diffuse breast enlargement rather than the firm, circumscribed abnormality seen in this patient. Educational objective: Physiologic gynecomastia is benign glandular proliferation of male breast tissue due to an imbalance between levels of estrogen and androgens. It is common in older (especially obese) men due to decreased testicular testosterone production and increased conversion of testosterone to estrogen in peripheral tissue. References: Gynecomastia: pathophysiology, evaluation, and management. (http://www.ncbi.nlm.nih.gov/pubmed/19880691)

A 66-Year-Old Man Is Found to Have Bilateral Breast Enlargement