Source:http://linkedlifedata.com/resource/umls/id/C0334410
NCI: A malignant neoplasm of the testis originating from interstitial (Leydig) cells.,NCI: A Leydig cell tumor characterized by large tumor size, and the presence of cytologic atypia, increased mitotic activity, necrosis, and vascular invasion. Approximately 10% of the testicular Leydig cell tumors show malignant characteristics and metastasize. Leydig cell tumors of the ovary follow a benign clinical course.