Leydig cell dysfunction and gynaecomastia in adult males treated with alkylating agents.

Three adult males presented with gynaecomastia, small testes and clinical features of androgen deficiency after treatment with alkylating agents. Laboratory evaluation revealed elevated serum follicle stimulating hormone and luteinizing hormone. Serum testosterone oenanthate relieved the symptoms of androgen deficiency in addition to reducing the size and tenderness of the gynaecomasia. It is postulated that in addition to the well documented effects of alkylating agents on the seminiferous tubules, a state of 'compensated Leydig cell dysfunction' in induced. The relative decrease in serum testosterone and concomitant lowering of the testosterone to oestrogen ratio may act as a stimulus for breast development. Therefore, treatment with exogenous testosterone would be expected to be effective.