COLON CANCER, WITH ANGIOGRAPHIC EVIDENCE OF VASCULITIS. I.D. Bucaloiu 1 , S. Dubagunta 1 , K.K. Pachipala 1 , N.R. Kamal 1 , F. Fata 1 ; 1 Geisinger Medical Center, Danville, PA (Tracking ID #76029) LEARNING OBJECTIVES: 5-Fluorouracil (5-FU) is one of the most commonly used chemotherapeutic agents in clinical oncology practice, alone or in different combinations. In stage III colorectal cancer, 5-FU based therapy has been shown to be associated with a survival benefit. We report a case of ischemic small bowel injury in a patient who received adjuvant chemotherapy with Oxaliplatin, 5-FU and LV and was found to have angiographic evidence of vasculitis in the superior mesenteric artery (SMA) territory. CASE INFORMATION: A 73 year-old male underwent a left hemicolectomy for Stage III colon cancer. He was enrolled in an adjuvant chemotherapy research protocol consisting of 5-FU 500-mg/m2 intravenous (IV) weekly boluses each over 1 hour, LV 500-mg/m2 IV weekly infusions each over 2 hours and Oxaliplatin (OP) 85 mg/m2 IV infusions every 2 weeks for 6 weeks followed by two weeks of rest. After the third weekly dose of cycle one of 5 FU/LV he presented with weakness, diarrhea, crampy abdominal pain and poor appetite. His abdomen was distended and he had heme positive stools. Stool cultures and clostridium difficile toxin antigen were negative. He was not neutropenic. Colonoscopy revealed dusky edematous changes in the ascending colon and focal ulceration with patchy submucosal hemorrhages in the distal ileum. Biopsies of the colon mucosa showed densely neutrophilic infiltrates of the lining epithelium and associated mild focal cryptitis. A SMA angiogram was performed and it revealed beading in ileal branches, consistent with the ischemic territory. Vasculitis serologies were negative. The patient was treated conservatively with hydration and IV antibiotics and later he was rechallenged with a 20% reduction of 5-FU dose with no recurrence of his symptoms in 12-month follow-up. IMPLICATIONS/DISCUSSION: Our patient had superficial erosions and ulcerations in the ileum as well as an ischemic appearance of the colon. The characteristic findings of``beading'' on the angiogram suggest an underlying ischemic mechanism related to 5 FU based therapy. This case will add to the series of patients reported with 5-FU induced vascular injury to the small bowel.