Clinics in diagnostic imaging (135). Cystic renal cell carcinoma.

A 45-year-old man presented with right flank pain and haematuria for one month. Computed tomography showed a large, well-circumscribed exophytic complex cystic mass with enhanced, irregular thickened walls arising from the upper pole of the right kidney, which was associated with bilateral renal stones. Partial right nephrectomy with removal of the right renal stones was performed. Histopathology revealed papillary cell carcinoma confined to the kidney. The patient made good postoperative recovery. The Bosniak classification system of renal cystic lesions and cystic renal cell carcinoma are discussed. Various cases of renal cystic lesions and cystic renal cell carcinoma are shown.