Retroperitoneal fibrosis presenting as acute renal failure.

BACKGROUND: A 60-year-old man with a history of atherosclerotic disease of the carotid and coronary vasculature presented with lower back pain and acute renal failure. Imaging studies revealed bilateral ureteral obstruction by a large retroperitoneal mass. INVESTIGATIONS: Physical examination, urine and blood analysis, catheterization, radiography of the chest, abdominal and pelvic CT, magnetic resonance angiography, renal ultrasound and biopsy of mass. DIAGNOSIS: Retroperitoneal fibrosis. MANAGEMENT: Ureteral stenting, laparoscopic ureterolysis, and immunosuppressive therapy with prednisone and mycophenolate mofetil.