Amyloid light chain and amyloid A protein, two types of gastrointestinal amyloidosis.

We have encountered rare cases of two types of gastrointestinal amyloidosis, amyloid light chain (AL) type and amyloid A protein (AA) type. Case 1: An 83-year-old man developed hematochezia after percutaneous coronary intervention. CT scans showed wall thickening of the colon. Colonoscopy revealed submucosal tumor-like protrusions with ulceration in the colon. Biopsies confirmed the diagnosis of colonic amyloidosis. Multiple myeloma-associated AL amyloidosis was suspected based on positive serum M-protein. Case 2: A 79-year-old woman with rheumatoid arthritis (RA) underwent esophagogastroduodenoscopy, which revealed multiple gastric erosions. Biopsies showed amyloidosis. AA amyloidosis with underlying RA was suspected.