Malignant Leydig cell tumor: objective tumor response to o,p'-DDD.

Leydig cell carcinoma of the testicle is a rare tumor with 16 well-documented cases in the medical literature. Radiotherapy and chemotherapy have not been successful in treating patients with metastatic disease. The patient described in this report had widely metastatic Leydig cell carcinoma associated with hypertension, hypokalemic alkalosis, and an elevated serum concentration of desoxycorticosterone. He experienced an objective clinical remission and disappearance of pulmonary metastases while receiving o,p'-DDD as the sole chemotherapeutic agent. This response was similar to that found in patients with adrenal cortical carcinoma. The regression of this tumor with an adrenolytic agent, in conjunction with the similar morphologic and biochemical features of these two types of tumors, provides additional evidence of the close similarity between Leydig cell carcinoma and adrenal cortical carcinoma.