[Malignant Leydig cell tumor of the testis secreting progesterone]

Malignant Leydig cell tumours of the testis occur in only 0.1-0.3% of patients with testicular tumours. Less than 50 cases of malignant Leydig cells tumours have been previously reported. A report of a new case is presented. This tumour was unusual because of high progesterone level. We analyzed malignant pathologic signs of Leydig cell tumours as immunohistochemical proliferation index. Management of this tumour, for which chemotherapy is not yet available, is discussed.