



This 69 y/o female presented with hematuria and diminished renal function. Renal ultrasound demonstrated left hydronephrosis. Retrograde pyelography was performed and a ureteral stent was placed. The selected image shown above demonstrates a filling defect in the proximal ureter with cut-off of the lower pole infundibulum. Abdominal and pelvic CT was subsequently performed without intravenous contrast due to the compromised renal function. The selected images shown above demonstrate abnormal thickening of the wall of the proximal ureter surrounding the ureteral stent with extension of the mass into the lower pole of the kidney. Transitional cell carcinoma infiltrating the kidney was suspected and subsequently confirmed at nephroureterectomy.