Table 4:

Common Representative Causes of Gynecomastia

Etiologies	Specific Causes
High estrogen level	Testicular tumors (germ cell tumor, Leydig cell tumor, Sertoli cell tumor); adrenal, liver, lung, and renal tumors; exogenous estrogen exposure; high body mass index; hyper- or hypothyroidism; starvation and refeeding; occupational exposure; use of isoflavones; exposure to phytoestrogens (in cosmetics, soy products, beer, tea tree oil, or lavender oil)
Low androgen level	Testicular trauma, orchitis, Klinefelter syndrome (47, XXY); pituitary disease; chemo-therapy; neurologic disease, spinal cord injury
Substance exposure	Alcohol, anabolic steroids, amphetamines, cocaine, heroin, marijuana
Pharmacologic agents	Alkylating chemotherapy agents, amiodarone, captopril, verapamil, cimetidine, diazepam, digitalis, haloperidol, isoniazid, metronidazole, nifedipine, omeprazole, phenytoin, spironolactone, tricyclic antidepressants, thiazide diuretics