1617 Colon Ischemia as Initial Presentation of Amyloidosis: A Rare and Challenging Diagnosis

Abstract

INTRODUCTION: Amyloidosis is a systemic disease rarely involving gastrointestinal tract (GIT) and requires a high index of suspicion to diagnose. GI presentations including abdominal pain, bleeding, malabsorption or protein losing enteropathy. Predisposing conditions are plasma cell dyscrasia, chronic inflammatory conditions or hemodialysis. We present case of Amyloidosis involving entire GIT presented with severe colon ischemia required total colectomy. CASE DESCRIPTION/METHODS: A 59-year-old man with 6 months history of abdominal pain, bloating and constipation. He tried laxatives with partial relief. A colonoscopy revealed ulcerations in the sigmoid colon with biopsies consistent with ischemic colitis. CT angiography of the abdomen showed patent vessels with no findings to explain ischemic changes. A colonoscopy repeated 3 months later showed persistent inflammation in the sigmoid colon. He, subsequently, was diagnosed with multiple myeloma and initiated on bortezomib and dexamethasone. A few weeks after initiating this treatment, he presented to ED with significantly worsened abdominal pain, distension and nausea. CT A/P revealed thickening from the rectum to the descending colon with proximal dilation, concerning for pneumatosis and ischemic colitis. He was taken emergently for a total colectomy with end ileostomy. Pathology revealed that he, in fact, had extensive amyloidosis (transmural, interstitial, and vascular involvement) with hemorrhage and necrosis throughout the removed colon as well as the removed portion of the ileum with positive margins. There have been prior reports of colonic ischemia after initiation of bortezomib however this does not appear to be culprit in this case given the patient’s findings on initial colonoscopy prior to starting the medication. DISCUSSION: Amyloid deposition infiltrates multiple organs. GIT involvement is common, rectal biopsy can confirm diagnosis. However, severe colon ischemia is uncommon presentation. Our patient presented with severe ischemic colitis and pneumatosis on CT scan. Prior to this, he had 2 colonoscopies, EGD, and abdominal fat biopsy all was non-diagnostic. He subsequently, had total colectomy, pathology revealed Amyloidosis. Duodenal biopsies confirmed small intestine amyloidosis. Colon ischemia due to Amyloidosis is rare. Diagnosis is challenging but can lead to detrimental consequences when it is delayed. Early diagnosis is critical in preventing progressive disease and potentially fatal complications.