Collecting Duct Carcinoma of the Kidney Mimicking Invasive Transitional Cell Carcinoma: A Case Report

ABSTRACT

Approximately 100 cases of collecting duct carcinoma have been reported in the medical literature. We herein report on a case of collecting duct carcinoma of the kidney in a 75-year-old patient. The abdominal sonography depicted a relatively poorly defined 7X6 cm sized, isoechoic mass lesion, as compared to the normal parenchyma, at the left kidney lower pole and the affected kidney showed preservation of the reniform shape. CT revealed a heterogeneous poorly defined low-attenuation mass that was mainly located in the medulla with involvement of the cortex and the lower half of the renal pelvis. Retrograde ureteropyelography showed a filling defect at the lower renal pelvis and severe narrowing of the left proximal ureter. We initially thought this lesion was invasive transitional cell carcinoma. Subsequent surgery confirmed a collecting duct carcinoma.