A case of small bowel perforation in diverticula due to secondary amyloidosis complicated with rheumatoid arthritis

We report a rare case of small bowel perforation in secondary amyloidosis in a 72-year-old Japanese woman under going treatment for rheumatoid arthritis. The patient developed severe abdominal pain during hospitalization for appetite loss. C-reactive protein was elevated. Abdominal computed tomography (CT) showed free air over the liver and ascites and intestinal dilation, necessitating emergency surgery for diffuse peritonitis secondary to 2 jejunal perforations. We conducted partial resection and reconstructive end-to-end jejunojejunostomy. Despite post-operative intensive care, her general condition failed to improve and she died of multiple organ failure on postoperative day 6. Postmortem diagnosis was gastrointestinal amyloidosis secondary to rheumatoid arthritis based on histological findings such as amyloid deposits within the muscularis mucosae layer and vascular smooth muscle and perforation in small bowel diverticula, and a marked increase in serum amyloid A (SAA) protein. Although gastrointestinal diverticula and perforation due to amyloidosis is very rare - this is, to our knowledge, the first such report in Japan - we assume the incidence will increase together with recent increases in rheumatoid arthritis. The prognosis of gastrointestinal perforation due to amyloidosis is dismal. Gastrointestinal amyloidosis should be considered a probable diagnosis in patients with acute abdomen and a history of rheumatoid arthritis.