A benign enlargement of the male breast secondary to glandular proliferation.
Attributed to altered sex-steroid signaling pathways with increased risk unopposed estrogen action on breast tissue.
Occurs in as many as 70% of pubertal males and approximately one-third of adults age 50-80 years.
Results from the imbalance of estrogen and androgen action at breast tissue.
May result from increase in free estrogens, decreases in free endogenous androgens, increased sensitivity to estrogens or androgen insensitivity at the breast tissue level.
Associated with physiologic changes of neonatal, pubertal and involutional status.
Related to testicular, adrenal and tumors with ectopic production of human chorionic gonadotropin.
Related to gonadal failure, secondary hypogonadism, liver disease, malnutrition with refeeding, dialysis, hyperthyroidism, androgen insensitivity syndromes, excessive extraglandular aromatase activity, testosterone production defects, idiopathic and drugs including estrogens, estrogen agonists, gonadotropins, antiandrogens, cytotoxic agents and alcohol.
Must be differentiated from breast cancer.
Usually have diffuse swelling and tenderness.
Typically presents as a subareola mass that is soft, compressible, and movable.
Skin dimpling and nipple retraction are generally not present with gynecomastia.
Pubertal disease is painful, tender and usually disappears within 1 year.
Adults with gynecomastia need to have assessment for alcohol, drug or medication abuse, liver kidney or lung dysfunction and for hypogonadism or hyperthyroid disease.
Can present bilaterally or unilaterally.
Three distinct patterns: nodular, dendritic and diffuse.
Occurs in up to 80% of patients who receive nonsteroidal anti-androgens such as bicalutamide, flutamide, or nilutamide, usually within the first 6-9 months after treatment onset.
Trial of an antiestrogen such as tamoxifen may be beneficial.
Persistence for more than 1 year is associated with fibrosis and will not respond to medications but requires surgical resection for treatment.
Most common type of breast lesion in men.
Prepubertal type is rare and should be considered pathological requiring assessment for the source of estrogen.
Very common in newborns and is typically seen in peripubertal boys and men over 50 years of age.
A specific cause for prepubertal disease is rarely found and 90% have idiopathic disease.
Etiology thought to be an imbalance of the levels of estrogen relative to androgen.
Elevated levels of estrogen in males can be due to obesity, exaggerates hormone/drug use, systemic diseases, gonadal failure, and estrogen secreting neoplasms among other reasons.