Sex cord-stromal testis tumors represent only 5% of all testicular neoplasms, and include Leydig, Sertoli, granulosa, thecal cell tumors, mixed cell types and undifferentiated tumors. We report a case of completely undifferentiated sex cord-stromal testis tumor, and discuss its diagnosis and treatment. To our knowledge only 2 other such cases have been reported in the literature.1 CASE REPORT A 39-year-old man presented with a 2-month history of painless increasing left testicular size. Physical examination revealed a firm mass of the left testis, and scrotal ultrasonography showed 2 dishomogeneous lesions of 30 and 33 mm within the left testis (right testis was normal). Serum -fetoprotein and -human chorionic gonadotropin were normal. The patient underwent left radical orchiectomy. Pathological examination demonstrated 2 well circumscribed, reddish masses of 35 and 32 mm. The surrounding testicular parenchyma, tunica albuginea and spermatic cord were normal. Microscopic examination revealed spindle and polygonal cells with eosinophilic cytoplasm arranged in sheets and nests (fig. 1). Immunohistochemical study showed positivity for vimentin, keratin and melanoma antigen recognized by T cell 1 (MART-1), weak positivity for Ki-67 and negativity for placental alkaline phosphatase, -fetoprotein and inhibin A (fig. 2). Based on histological and immunohistochemical patterns, undifferentiated sex cord-stromal testis tumor was diagnosed. Computerized tomography of the chest and abdomen did not demonstrate metastatic lesions. Unilateral nerve sparing retroperitoneal lymphadenectomy was performed, with no evidence of metastases. At 12 months postoperatively the patient was disease-free. DISCUSSION
