Case Presentation: A 39-year-old Bulgarian man, recently diagnosed with non ischemic cardiomyopathy was transferred to our hospital due to upper gastrointestinal bleeding. The patient reports seven months of intermittent hematemesis that worsened after two significant episodes of vomiting bright red blood. The patient became hemodynamically unstable in spite of aggressive fluid resuscitation and blood transfusion, requiring vasopressors. Emergent esophagogastroduodenoscopy was performed, showing multiple medium-sized mucosal papules with bleeding and stigmata of recent bleeding in cardia, gastric fundus and gastric body. Gastric biopsies revealed extensive amyloid deposition in the lamina propria and submucosa, with Congo red stain demonstrating apple-green birefringence under polarized light. Fat pad biopsy was also positive for amyloidosis. Liquid chromatography mass spectrometry identified amyloid subtype as AL amyloidosis, kappa type. Serum and urine immunofixation confirmed the presence of monoclonal immunoglobulin kappa paraprotein. Serum-free kappa light chain assay was elevated at 140 mg/dl and free lambda was 57.40 mg/dl. Kappa/lambda ratio was 2.4. Bone marrow flow cytometric analysis detected a kappa light chain restricted plasma cell population. By immunohistochemical stains performed on the biopsy, CD138 positive plasma cells were increased and comprised approximately twenty percent of nucleated cells. In order to identify extension of the disease, further studies were obtained. EKG showed low voltage and pseudo-anteroseptal infarct. A transthoracic echocardiogram revealed moderately increased wall thickness. Bilirubin and alkaline phosphatase were elevated. Other labs were significant for anemia and elevated INR.

Discussion: Amyloidosis is a heterogenous term that refers to the disruption of tissue structure and function secondary to the deposition of insoluble fibrils. One of the most common cause of systemic amyloid deposition is AL amyloid, caused by a plasma cell dyscrasia. Clinical manifestations depend on the location and amount of deposition. When gastrointestinal involvement occurs, mucosal infiltration leads to polypoid protrusions and mucosal thickening. Only a third of those patients will present with GI bleeding. Its pathophysiology seem to be related to local ischemia, vascular friability and mucosal injury causing erosions, hematomas or ulcerations.

Conclusions: Cases with biopsy diagnosed disease and clinically apparent GI involvement are very rare. The endoscopic appearance of gastric amyloidosis can closely resemble that of gastric malignancy. Although unspecific, staining for amyloid should be considered in patients undergoing gastrointestinal biopsy and findings consistent with an infiltrative process. Due to the aggressiveness of the disease and the consequences of delayed recognition, a high degree of suspicion should be kept in these patients.