Testosterone and estradiol levels in male gynecomastia. Clinical and endocrine findings during treatment with tamoxifen

: Oestradiol-(E2) levels in serum were significantly higher in a group of 91 males with gynaecomastia than in a control group. The levels were highest in patients with testicular tumour, hyperprolactinaemia and idiopathic gynaecomastia. In gynaecomastia of puberty and primary or secondary hypogonadism, the E2 level was within normal limits, but the testosterone/oestradiol ratio was significantly reduced. Tamoxifen, at a daily dose of 20 mg, was administered over 2-4 months to 16 patients with gynaecomastia. Of twelve patients with painful gynaecomastia ten became painfree. Gynaecomastia regressed partially or completely in 14 patients, in only 2 was it unchanged. There was no recurrence of gynaecomastia after discontinuing tamoxifen. Side-effects did not occur. It is concluded that tamoxifen is a promising alternative to the surgical treatment of gynaecomastia.