Amyloidosis-induced gastrointestinal bleeding in a patient with multiple myeloma.

We present a case of multiple myeloma (MM) complicated by recurrent amyloidosis-induced gastrointestinal bleeding. The patient presented with episodes of coffee-ground vomitus or massive hematochezia. No bleeding focus could be identified using endoscopy, a red blood cell scan, or angiography. Finally, a tissue biopsy taken at the irregular mucosa beside protruding vessels in the duodenum confirmed the diagnosis of gastrointestinal amyloidosis. As this case illustrates, the absence of systemic symptoms of amyloidosis and nonspecific endoscopic findings in gastrointestinal amyloidosis may make diagnosis difficult. Therefore, we recommend that a diagnosis of amyloidosis-induced gastrointestinal bleeding should be considered in patients with MM with an obscure hemorrhage.