Transitional cell carcinoma of the renal pelvis with extension into the inferior vena cava: a report of two cases.

Of all primary malignant renal tumors, 10% to 15% originate from the renal pelvis, and 90% to 92% of these tumors are transitional cell carcinomas. Nonetheless, renal pelvis transitional cell carcinoma extending into the inferior vena cava is very rare. We report one confirmed case and one highly suspicious case of renal pelvis transitional cell carcinoma with a tumor thrombus in the inferior vena cava. Both of our patients died within 6 months of initial diagnosis, indicating the poor prognosis and advanced stage of transitional cell carcinoma with an inferior vena cava thrombus. Transitional cell carcinoma should be considered in patients with obstruction of the renal vein and the inferior vena cava.