We describe a case of renal leiomyoma in a 21-year-old woman who presented with flank pain and hematuria. Urographic and computed tomographic (CT) studies revealed a large right renal mass with polypoid outgrowth protruding into the renal pelvis. Cortical renal leiomyoma with this radiographic manifestation is extremely rare.

Collecting duct carcinoma is a rare type of renal cell carcinoma. It is usually diagnosed pathologically and carries a poor prognosis. Renal cell carcinoma arising within a cyst is also rare. We report a case of collecting duct carcinoma presenting as a giant, bleeding complicated renal cyst with minimal solid component. The patient had a relatively long survival after nephrectomy.