2561 Not All That Ulcerates Is Crohn's: A Malignant Mimic of Small Bowel Crohn's Disease

Abstract

INTRODUCTION: Capsule endoscopy (CE) is indicated in the evaluation of suspected Crohn's disease (CD) when ileocolonoscopy and radiographic studies are negative or inconclusive. However, it should be recognized that mucosal breaks or ulcers alone are not always diagnostic of CD. CASE DESCRIPTION/METHODS: A 55 year-old man from India who immigrated to the US as a child was admitted to an outside hospital with 6 months of bilateral lower quadrant abdominal pain and iron-deficiency anemia. After normal upper endoscopy and colonoscopy, CE showed an ulcer and inflamed mucosa in the ileum. On this basis he was diagnosed with CD and treated with prednisone. The next month he was admitted to our institution with ongoing abdominal pain and unintentional weight loss but no diarrhea or hematochezia. On exam his vital signs and body mass index were normal. His abdomen was soft without organomegaly or palpable mass. He was tender to palpation in the bilateral lower quadrants. Stool was brown. Laboratory results were Hgb 8.3 g/dL, iron studies consistent with iron-deficiency, albumin 2.8 g/dL, C-reactive protein 150 mg/L, and erythrocyte sedimentation rate 45 mm/hr. CT enterography showed wall thickening of the mid-ileum with mucosal enhancement and mesenteric root adenopathy. Retrograde double balloon enteroscopy 90 cm into the ileum revealed a 15 mm shallow ulcer 80 cm proximal to the ileocecal (IC) valve and a similar ulcer 15 cm proximal to the IC valve. Biopsies showed ulcerated mucosa with infiltrating atypical cells that stained positive for ERG, a highly specific endothelial marker, and negative for other immunostains, leading to a diagnosis of primary intestinal angiosarcoma. DISCUSSION: Primary intestinal angiosarcoma is a rare soft tissue sarcoma that may present with abdominal pain, GI bleeding, obstruction, or weight loss. Tumors, detected on 2-4% of CEs, are in the differential diagnosis for small bowel CD along with infection, ischemia, vasculitis, lymphoma, Behcet disease, radiation enteritis, and drug-induced enteritis. In suspected CD, there is no reference standard or uniform criteria for diagnosis by CE. And, many of the lesions that lead to a diagnosis of CD are non-specific with the specificity of CE for CD as low as 53% and the positive predictive value <60% in some studies. Thus, findings of CE should be interpreted with an adequate degree of skepticism and a broad differential diagnosis considered to minimize mimics being mistaken for CD.