Occult Gastrointestinal Bleeding Secondary to Gastric Amyloidosis in an HIV-Infected Patient

Abstract

Purpose: Amyloidosis is an abnormal intercellular deposition of amyloid fibrils composed of monoclonal light chains. It commonly manifests as a systemic involvement of multiple organs and localized involvement is relatively rare. Methods: A 65 year old Caucasian male with a history of HIV/AIDS (CD4 count: 148/cu.mm), Hepatitis C, CKD, CVA, anoxic encephalopathy, chronic respiratory failure on HAART was sent from a nursing home secondary to anemia. Physical examination revealed pallor, distended abdomen and moderate tenderness in bilateral lower quadrants. Laboratory values showed iron-deficiency anemia and positive FOBT. CT Abdomen showed evidence of colonic diverticulosis. He received intravenous hydration, PPI, and blood transfusions. Esophagogastroduodenoscopy showed erythematous mucosa and gastric erosions in the antrum; biopsies were consistent with gastric amyloidosis (See images). Clinical course was complicated by pneumonia, C. difficile colitis and septic shock; patient expired on day 31 of hospitalization. Results: GI involvement in systemic amyloidosis is quite common (70%). However, localized GI amyloidosis is exceedingly rare. The most common sites of GI involvement are the descending duodenum (100%), stomach and colorectum (90%), and the esophagus (70%). Symptoms may be secondary to polypoid protrusions, mucosal friability, erosions, and ulcerations. AL-type amyloid is the most common type of amyloid deposit seen in solitary amyloidosis of the GI tract. The characteristic histological feature is amorphous material with apple green birefringence under polarized light after Congo red staining. Conclusion: Gastrointestinal amyloidosis should be considered in the differential diagnosis of occult GI bleeding.Figure: [103] Gastric Amyloidosis - HE Staining.Figure: [103] Gastric Amyloidisis - Congo Red Staining.