Adult cystic Wilms' tumor (nephroblastoma): radiologic features with pathologic correlation.

Wilms' tumor is an uncommon disease in adults. Wilms' tumor typically presents as a large complex mass with cystic component and varying degrees of vascularity. The previously reported radiologic findings have reflected this complex appearance. We present a case of cystic Wilms' tumor in an adult patient. The tumor presented as a large, rapidly growing, hypovascular, multicystic mass with minimal solid component which showed as septation on ultrasound, contrast enhanced CT, and MR studies. The preoperative findings were suggestive of multilocular cystic nephroma. We suggest that Wilms' tumor should be included in the differential diagnosis of a patient who presents with a large, rapidly growing, multicystic renal mass.