Is it transitional cell carcinoma or renal cell carcinoma on computed tomography image?

We report on a 58-year-old female patient with renal cell carcinoma simulating transitional cell carcinoma on computed tomography. The computed tomography scan showed an enhancing 2.5-cm left renal pelvic mass without renal parenchymal mass. Urinalysis revealed microscopic hematuria. Cystoscopy and urine cytology was negative for transitional cell carcinoma. Laparoscopic nephroureterectomy was done under the preoperative diagnosis of localized transitional cell carcinoma of the renal pelvis according to the computed tomography findings. The histologic result, however, was a clear cell renal cell carcinoma.