[Concurrent perirenal liposarcoma associated with renal cell carcinoma]

Here, we present a case of concurrent perirenal liposarcoma associated with renal cell carcinoma (RCC) in a 60-year-old man. The tumor was detected by ultrasonography, computed tomography and magnetic resonance imaging. However, the preoperative qualitative diagnosis was difficult due to unusual image findings. The patient was treated by surgical resection and has been free of disease for 24 months. To our knowledge, this is the third case of RCC associated with primary retroperitoneal liposarcoma reported to date. We discuss the imaging and pathological findings of the case and review the relevant literature.