Retroperitoneal fibrosis: a rare cause of recurring abdominal pain.

Retroperitoneal fibrosis (RPF) is a rare condition of unclear aetiology. It is believed to be immune-related. About two-thirds of cases are thought to be idiopathic.' We present a case of idiopathic RPF in a 37-year old male with recurring abdominal pain over a five-month period associated with features of ischaemic colitis and bilateral hydroceles. An initial CT scan ofthe abdomen showed a significant peri-aortic soft tissue mass .The inferior mesenteric artery (IMA) was noted to pass through the mass and to be compressed by this mass. A subsequent CT-guided biopsy confirmed retroperitoneal fibrosis. He was successfully treated with steroids only with resolution of his symptoms and radiological features. To our knowledge no case of idiopathic RPF, presenting with features of ischaemic colitis and bilateral hydroceles, has been reported in the UK. CASE REPORT Mr RS, a 37-year old male, first presented to the Trust via his General Practitioner with a three-week history of intermittent sharp flank and left iliac fossa (LIF) pains radiating to his left testicle. He had no significant past medical history. Examination revealed some tenderness inthe left loin and left iliac fossa areas with no other remarkable findings. CRP and ESR were significantly elevated but other baseline laboratory tests were normal. He had an Ultrasound Scan (USS) ofthe abdomenwhich was essentially normal. His symptoms settled with conservative management and he was discharged a few days later. He was however readmitted a week later with a recurrence of the LIF pain but this time associated with bloody diarrhoea. Repeat investigations including Clostridium difficile were all normal except CRP, which was again significantly elevated. He Fig 1. Initial Barium Enema: normal.