Renal cell carcinoma dwelling upon a renal cyst wall and laparoscopic management.

INTRODUCTION Simple renal cysts are mostly benign and asymptomatic disease and managed conservatively. Renal cell carcinomas (RCC) sometimes presents as a cystic tumor. At least 4-15 % of renal tumors encountered are cyst-associated renal cell carcinoma (CRCC). (1) Findings suggestive of malignancy in a renal cyst include thickened, irregular or smooth walls or septa, and enhancement after contrast injection.(2) Some cystic RCC are known to arise from simple renal cysts. Transformation of a simple renal cyst into RCC, however, is extremely rare.(1,3) According to our knowledge no reports have demonstrated a clinical course of RCC dwelling upon a renal cyst wall (or localized at outer side of cyst wall). We describe a laparoscopic decortication of a simple renal cyst with an overlaying RCC.