Gynecomastia

Gynecomastia is a benign enlargement of glandular breast tissue in males. Clinically it is recognized as a rubbery or firm disc of subareolar tissue 2 cm or more in diameter, centred under the nipple. Pseudogynecomastia (lipomastia) is soft fatty enlargement without that glandular disc and is common with obesity. Both can look alike, so the distinction is made on palpation and clinical assessment, not on appearance. Mechanism: estrogen stimulates breast ductal growth and androgens oppose it. Anything that raises the estrogen-to-androgen ratio can produce gynecomastia: more estrogen (estrogen- or hCG-secreting tumours, increased aromatase activity in adipose tissue, hyperthyroidism), less androgen (primary or secondary hypogonadism, Klinefelter syndrome), blocked androgen action (spironolactone, bicalutamide, flutamide, cyproterone) or displacement of estrogen from sex hormone-binding globulin. Liver cirrhosis, kidney failure, HIV infection, refeeding after malnutrition and spinal cord disorders are also associated with it. Epidemiology that matters for nursing: gynecomastia has three physiologic peaks. Newborns develop breast tissue from maternal estrogen. In puberty, Endotext reports clinically detectable gynecomastia in up to 60% of boys by age 14 years, while the Pediatric Endocrine Society states it...