Colonic Calciphylaxis and Recurrent Gastrointestinal Bleeding in a Patient with ESRD: A Multidisciplinary Challenge

Introduction: Calciphylaxis is a rare but serious complication in patients with ESRD, typically involving the skin. Visceral involvement, particularly of the gastrointestinal (GI) tract, is exceedingly uncommon and can present with life-threatening bleeding. Case Description: A 41-year-old woman with ESRD on peritoneal dialysis, diabetes, hypertension, and cardiovascular disease presented for peripheral artery disease evaluation and underwent a right lower extremity angioplasty. She subsequently developed multifocal strokes and a cerebral venous sinus thrombosis requiring anticoagulation. GI bleeding occurred shortly after. Endoscopy revealed diffuse rectosigmoid ulcerations. Given this and other findings, a concern for a vasculitis was present. Cryoglobulins returned positive so steroids were started. Biopsies showed sevelamer crystals deposited in the GI tract and this was postulated as a potential cause of ulcerations, so this medication was stopped. Repeat cryoglobulin was negative, and steroids were stopped. GI bleeding stabilized after holding of anticoagulation and she discharged in stable health. She was soon re-admitted with small bowel obstruction, recurrent hematochezia, and eventually underwent exploratory laparotomy with sigmoidectomy with end colostomy. Histologically, the sections of the sigmoid colon showed diffuse transmural ischemic necrosis. The small and medium sized arterioles showed calcium deposits in vessel walls associated with intravascular fibrin thrombi. Intravenous sodium thiosulfate at 25gm IV after each dialysis session was started based on these findings. Optimization of phosphorous, calcium and PTH were done as well. Recurrent bleeding did not occur and she was discharged in stable health. Discussion: This case highlights a rare presentation of calciphylaxis in the sigmoid colon, complicated by recurrent GI bleeding. The absence of skin findings delayed recognition, and diagnosis was only made on surgical pathology. Many other etiologies were suspected such as vasculitis and sevelamer colitis before the final diagnosis was made. Management and diagnosis required close coordination across multiple specialties. Sodium thiosulfate was initiated based on colonic pathology. Visceral calciphylaxis should be considered in ESRD patients with unexplained GI bleeding.