Gynecomastia and Leydig cell tumors in the adult1
Two men with gynecomastia were evaluated at The Cleveland Clinic Foundation. Both were subsequently found to have a Leydig cell tumor of the left testis. One patient had previously undergone a testicular biopsy examination because of presumed infertility; the other had undergone the same type of examination due to a suspicious enlargement of the testicle. The results of these examinations had failed to reveal any evidence of a tumor. Endocrinologic manifestations of Leydig cell tumors are common and frequently present prior to the discovery of a testicular mass. These tumors are rare and usually benign. An orchiectomy is then curative and results in resolution of hormonal abnormalities in most cases. When malignant, Leydig cell tumors usually become evident by the presence of metastasis.