Renal cyst wall thickening following percutaneous aspiration.

Computed tomography (CT) is an accurate and efficient means for evaluating and characterizing renal masses. Using established criteria, benign cortical cysts may be accurately differentiated from complex cysts or solid renal lesions. We report a case of cyst wall thickening simulating a cystic tumor that occurred after percutaneous aspiration of a simple renal cyst.