[Male infertility in an adult with unilateral Leydig cell tumor of the undescended testis].

We report a case of Leydig cell tumor of the postpubertal cryptorchid testis with the chief complaint of male infertility. A 36-year-old man had consulted another clinic and his semen analysis revealed oligospermia. A solid mass was palpated in the right inguinal undescended testis. He was referred to our hospital for treatment of the testicular tumor. Right inguinal orchiectomy was performed and pathological diagnosis was Leydig cell tumor with no malignant findings. After the surgery improvement was seen in his semen analysis. There was no evidence of recurrence 9 months after surgery.