Retroperitoneal fibrosis during the course of ulcerative colitis. A simple coincidence?

Retroperitoneal fibrosis has been described as a rare occurrence during the course of inflammatory bowel disease, mainly Crohn's disease. This is the third report on retroperitoneal fibrosis occurring during the course of ulcerative colitis. A 62-year-old male patient with a 5-year history of ulcerative colitis developed stenosis of the left ureter due to retroperitoneal fibrosis. Treatment consisted in surgically releasing the ureter from the mass and steroids. During a 2.5-year follow-up, renal function was stable and ulcerative colitis in remission. Important aspects of this case are the moderate course of ulcerative colitis, ultrasound confirmation of normal kidney structure before manifestation of fibrosis, hypertension diagnosed four years before retroperitoneal fibrosis, a non-functioning kidney at diagnosis, and reduction of retroperitoneal mass after steroid treatment. Retroperitoneal fibrosis, although a rare disease entity should be considered when a patient with ulcerative colitis develops otherwise unexplained renal insufficiency.