Estrogen and progesterone receptors in gynecomastia

The etiology of gynecomastia is unknown. There seems to be no increased inc idence of malignancies in patients with idiopathic gynecomastia; however, p atients with Klinefelter syndrome exhibit an increased incidence of maligna ncy. The authors reviewed the results of 34 patients with gynecomastia diag nosed in adolescence who, following initial evaluation, had a mastectomy. T he estrogen and progesterone receptors were analyzed in these patients. Thr ee of the patients were diagnosed with Klinefelter syndrome. These three pa tients exhibited elevated amounts of estrogen and progesterone receptors. N one of the patients who were not diagnosed with this syndrome demonstrated significant elevation of their estrogen or progesterone receptors. The pres ence of elevated estrogen and progesterone receptors in patients with Kline felter syndrome provides a potential mechanism by which these patients may develop breast neoplasms. The absence of elevated estrogen and progesterone receptors in patients with idiopathic gynecomastia may serve to clarify wh y these patients' disease rarely degenerates into malignancy.