METACHRONOUS DEVELOPMENT OF MALIGNANT LEYDIG-CELL TUMOR

Leydig cell tumor (LCT), a rare testicular tumor, is malignant in only about 10% of the cases. We report the case of a patient with bilatera l malignant LCTs that developed metachronously. After undergoing a rig ht inguinal orchiectomy for a malignant LCT at the age of 43 years, th e patient was given cisplatin-based chemotherapy for suspected para-ao rtic lymph node metastasis. Eighteen months after the right orchiectom y, examination of a left testicular biopsy specimen showed a malignant LCT and a left inguinal orchiectomy was performed. Histologically, th e initial malignant LCT exhibited a highly pleomorphic appearance with mitotic figures (58/10 HPF), whereas the second malignant LCT showed fewer mitoses (2/10 HPF). The proliferating cell nuclear antigen (PCNA )-labelling index in these tumors also differed (right-sided tumor, 50 %; left-sided tumor, 28%). These findings suggest that the malignant L CT in the left testis developed as a second primary rather than as a m etastatic tumor. There have been no known similar cases, although thre e cases of malignant LCT with contralateral metastasis have been repor ted, Copyright (C) 1997 by W.B. Saunders Company.