Leydig cell tumor of testis.

In adult patients with Leydig cell tumor of the testis, endocrinologic signs occur in 30 per cent of the cases and often precede the onset of a palpable testicular mass. Gynecomastia is the most common endocrinologic manifestation and probably is due to increased estrogen secretion by the Leydig cells. In the patient with adrenogenital syndrome and testicular enlargement it is difficult to distinguish Leydig cell tumor from adrenal rest hypertrophy. Four patients with Leydig cell tumor and endocrinologic manifestations are discussed; three are adults who presented with gynecomastia and the fourth is a patient with congenital adrenogenital syndrome. In the adult patient inguinal orchiectomy is the treatment of choice, while in the patient with adrenogenital syndrome initial management by high-dose steroid suppression should be attempted prior to testicular exploration.