[Excessive gynecomastia in boys. Effective medical treatment using danazol (Winobanin)].

The purpose of this study was to provide a medical alternative to mastectomy in boys with excessive breast development. Eleven boys with bilateral gynecomastia, ranging in size between 9 X 7 cm and 3 X 3 cm in diameter, were treated with 200 mg of Danazol daily for 6 months. This therapy led to a reduction in breast size between 3 X 3 cm and 1,5 X 1,5 cm. The antigonadotropic action of Danazol was documented by inhibition of basal gonadotropin secretion, by disappearance of normal sleep dependent rhythms and by a reduced pituitary response to stimulation. Simultaneously, plasma testosteron secretion was suppressed without reduction of testicular volumes. In all patients the hypothalamo-pituitary gonadal axis normalized within 67 months after termination of therapy and no relapse was observed over a control period up to 26 months. The continuing regression after Danazol treatment emphasizes the effectiveness of drug therapy as an alternative regimen to surgical intervention.