[Testicular Leydig cell tumor presenting as male infertility: a case report].

A Leydig cell tumor is a rare disease entity occurring in the testis. Occasionally it is considered to be related to male infertility. We report a case study of a Leydig cell tumor in a single testis presenting as male infertility. A 38-year-old male was referred to our hospital because of a tumor in his right testis. He had undergone left orchiectomy at one year old because of a testicular tumor. During an examination related to the infertility, ultrasound revealed a 1 cm tumor. Tumor markers were all within normal ranges.Hormonal examination showed that luteinizing hormone (LH) 30.3 mIU/ml (1.5-12.4) and follicle stimulating hormone (FSH) 11.9 mIU/ml (1.7-8.6) were higher than normal limits, but total testosterone(total T) and estradiol (E2) were within normal ranges. Tumor enucleation was first performed, and then testicular sperm extraction (TESE) was carried out from a macroscopically normal site of the testis.Histopathological diagnosis was a benign Leydig cell tumor surrounded by Leydig cell hyperplasia. For 12 months after the operation there has been no recurrence. Although high LH and FSH persisted, total T and E2 were within normal ranges.