Bilateral renal cell carcinoma in a horseshoe kidney: preoperative assessment with MRI and digital subtraction angiography

Renal cell carcinoma in a horseshoe kidney is an unusual entity. To our kno wledge, only 123 cases have been published to date. We report the first bil ateral case of two clear-cell carcinomas in an asymmetrically fused kidney. Optimum preservation of renal function after radical tumor removal require s accurate preoperative imaging. Since the vascular supply in fusion anomal ies is extremely variable, angiography is mandatory. Magnetic resonance ima ging was most suitable to predict the tumor extent and localization, becaus e it simultaneously gave the most comprehensive anatomical overview of the malformation.