[Sarcomatoid carcinoma of the renal pelvis: a case report]

A 65-year-old man visited our hospital with the complaint of left hypochondrial pain. Since he had left giant hydronephrosis due to ureteral stone, we performed left nephrectomy. Unexpectedly, macroscopic examination of the resected kidney revealed multiple yellowish nodules located in the renal pelvis and calyces. Histopathologically the nodules consisted of two pattern of malignancy, transitional cell carcinoma and spindle sarcomatous tumor. Immunohistochemical examination showed that spindle cells were stained positive for cytokeratin, and the final diagnosis was sarcomatoid carcinoma of left renal pelvis. Postoperatively, the patient underwent two courses of adjuvant chemotherapy, but metastases to retroperitoneal lymph nodes were noted two months after operation. He died of the disease eight months postoperatively.