Renal cell carcinoma growing into the renal pelvis and mimicking transitional cell carcinoma: A case report and literature review.

Renal cell carcinoma (RCC) originated from parenchyma and the majority of malignancies originating in the renal pelvis are transitional cell carcinoma (TCC). In the present study, a rare case of RCC growing into the renal pelvis and mimicking TCC in medical imaging is reported. The preoperative differentiation between RCC and TCC is important in order to identify the type of surgical treatment required: Nephrectomy or ureteronephrectomy. The role of ureteroscopy and biopsy is emphasized in the accurate preoperative diagnosis of a renal pelvic mass. Thus, the present study provided fundamental evidence for the pathogenesis of RCC with pelvic extension and challenged the present tumor node metastasis staging system of RCC.