[Retroperitoneal xanthogranuloma: a case report].

A 48-year-old man was admitted to our hospital for lumbago. Computerized tomographic (CT) scan, aortography and venacavography indicated a solid retroperitoneal tumor at the right renal hilus. The tumor was removed and right nephrectomy was conducted. Some of the tumor remained owing to strong adhesion to the inferior vena cava and lumbar spine. Histological diagnosis of the resected tumor was retroperitoneal xanthogranuloma. One year after surgery, the CT scan revealed a gradual decrease in size of the remaining retroperitoneal mass.