Gastric amyloidosis associated with multiple myeloma: A rare cause of upper gastrointestinal bleeding

Amyloidosis is defined as an excess extracellular deposit of protein fibrils, an associated syndrome with tissue injury and dysfunction. Light chain (AL) amyloidosis is the most common type of systemic amyloidosis. The most frequently involved organs are the kidneys, heart, liver, autonomous nervous system, and gastrointestinal tract. Systemic AL amyloidosis patients often have GI symptoms such as diarrhea and vomiting. Furthermore, asymptomatic gastric amyloid deposits are commonly found in patients with systemic AL amyloidosis. The clinical manifestations, laboratory results, and treatment of an 80-year-old female patient with AL amyloidosis of the gastrointestinal tract in our hospital were summarized. Relevant literatures on the etiology, clinical features, diagnosis, treatment, and prognosis of this disease were reviewed. The patient was referred to upper endoscopy because of melena for weeks. Large areas of irregular thickened gastric folds with overlying ulcers and friable polypoid masses at the fundus were seen, showing amyloid depositions. Further workup revealed that no involvement of other organs. Serum immunoelectrophoresis and bone marrow biopsy confirmed multiple myeloma, which was clinically thought to cause gastric amyloidosis. The patient was treated with melphalan, prednisolone, and thalidomide. After treatment, the melena was improved, the flattening gastric mass and a reduction in the serum kappa light chain level and kappa/lambda ratio were observed. Gastric amyloidosis is rarely seen at upper endoscopy in patients without a previously established diagnosis of myeloma. Early detection of gastrointestinal amyloidosis will ultimately improve the outcomes of patients with the rare disease.