Introduction Benign breast enlargement in males secondary to increased effective estrogen can be increased production or decreased degradation also result of decrease in androgens leaving estrogens unopposed May occur naturally throughout male life newborn secondary to high maternal estrogen puberty elderly secondary to androgen decrease Associated conditions cirrhosis genetic diseases Klinefelter syndrome login to view 2 more bullets testicular feminization cancer choriocarcinoma of testis login to view 1 more bullet drugs estrogen marijuana flutamide login to view 1 more bullet leuprolide login to view 1 more bullet psychoactive drugs "Some Drugs Create Awesome Knockers" login to view 8 more bullets