Renal cell carcinoma with renal pelvic extension simulating transitional cell carcinoma: a case report.

A case of renal cell carcinoma (RCC) with unusual extension into renal pelvis is reported. The radiographic findings simulate closely to those of transitional cell carcinoma (TCC) of the renal pelvis. Histopathological study of the extirpated tumor revealed RCC with invasion of renal pelvis. It is emphasized that it is occasionally difficult to distinguish TCC with renal invasion from RCC with renal pelvic extension. In addition, decision of surgical approach should be considered preoperatively in these cases.