Malignant Leydig cell tumor of the testis in complete remission on o,p'-dichlorodiphenyl-dichloroethane.

A 56-year-old patient is described who presented with retroperitoneal lymph node metastases 2 years after resection of a Leydig cell tumor of the left testis. The patient did not suffer from endocrinological imbalance. Surgical removal of the metastases alleviated abdominal symptoms for 1 year. o,p'-Dichlorodiphenyl-dichloroethane (o,p'-DDD) treatment was started at the time of recurrence of the retroperitoneal mass and the appearance of a hepatic metastasis. Tumors were remarkably responsive to o,p'-DDD, since 2 complete remissions could be obtained for extended periods. The o,p'-DDD was tolerated reasonably well and serum levels of 15 to 20 mg./l. were sustained for many months. Unfortunately, the patient could not be cured with this effective treatment.