2757 Gastric Amyloid: The Patient Who Could Not Eat at AL

Abstract

INTRODUCTION: Gastroparesis is defined as delayed gastric emptying in the absence of mechanical obstruction. Diabetes and medication side effects are common causes. AL amyloidosis is a systemic disease due to extracellular fibril deposition that can affect multiple organs. Gastro-intestinal (GI) involvement is less common than in other organ systems but can present in many different ways, including gastroparesis. CASE DESCRIPTION/METHODS: A 77 year old non-diabetic man from Mississippi presented with a one year history of intermittent abdominal distention, nausea and bloating. In addition, he had increasing dyspnea on exertion and lower extremity edema. Outside work-up consisted of multiple imaging studies demonstrating marked gastric distention as well as delayed gastric emptying (Figures 1 and 2). Outside colonoscopy was unrevealing and EGD was negative except for a distal esophageal ulcer and focal active duodenitis. He was started on a PPI and trialed on an alternating regimen of metoclopramide and erythromycin, without symptomatic relief. He was referred to our hospital for further diagnostic work-up. Repeat colonoscopy showed congested distal ileal mucosa and friable ascending colonic mucosa. Biopsies from both sites revealed amyloid deposits by Congo red stain (Figure 3). Serum protein electrophoresis noted a monoclonal IgG lambda peak with M-spike of 1.5 g/dL and bone marrow biopsy revealed approximately 70% of marrow cellularity consisting of plasma cells. Echocardiogram confirmed severely increased concentric left ventricular wall thickening consistent with cardiac amyloidosis. Interestingly, neither fat pad biopsy nor bone marrow biopsy showed presence of amyloid. The patient was diagnosed with myeloma and AL amyloidosis with gastro-intestinal and cardiac involvement. DISCUSSION: This case highlights the broad differential for gastric distention and dysmotility. When the ‘usual suspects’ such as diabetes, medication, post-surgery and neurological disease have been ruled out, rarer causes like an infiltrative process should be considered. Common manifestations of GI tract amyloidosis include GI bleeding, malabsorption, protein-losing enteropathy and chronic dysmotility. The diagnosis of amyloidosis is based on positive tissue diagnosis. While the combination of a fat pad and a bone marrow biopsy has a high sensitivity (89%) for diagnosing AL amyloidosis, negative results do not rule out amyloid elsewhere and tissue sampling from the affected organ site is essential, as demonstrated in this case.