Sarcomatoid carcinoma of the renal pelvis

A sarcomatoid carcinoma of the urinary system is a rare malignant tumor, composed of both epithelial and stromal cells, is regarded as a similar disease entity to a carcinosarcoma. In Korea, only 1 case of primary sarcomatoid carcinoma and 4 cases of carcinosarcoma involving the bladder have been reported, but to date, no case of primary sarcomatoid carcinoma involving the renal pelvis has been reported. Recently, we experienced a case of sarcomatoid carcinoma involving the right renal pelvis in a 67-year-old male patient with intermittent gross hematuria. A CT scan demonstrated a 5×4cm sized mass in the right renal pelvis. Under the diagnosis of a right renal pelvic tumor, a right nephroureterectomy, with bladder cuff excision, was performed. The tumor was composed mostly of pleomorphic spindle cells, and in the peripheral part of the tumor and renal pelvis, a high grade transitional cell carcinoma and adenocarcinoma was also found. The tumor was pathologically confirmed as a primary sarcomatoid carcinoma of the renal pelvis.