Perforation and tumor formation of the intestine in primary amyloidosis.

We report a case of primary amyloidosis with repeated bowel perforations. This patient also had localized amyloid deposition creating a tumorous region mimicking malignancy in the rectum. Perforation of the intestine is common in systemic amyloidosis. The ischemic change due to amyloid infiltration into the vessel wall may lead to perforation of the affected bowel. Amyloid tumors occur more often in localized amyloid than in systemic amyloidosis. Macroscopically, it is difficult to distinguish amyloid tumor of the intestine from neoplasia.