Clinical Recognition of AL Type Amyloidosis of the Luminal Gastrointestinal Tract

Background & Aims: Amyloidosis is characterized by the pathologic deposition of specific proteins throughout the body. Gastrointestinal involvement with amyloid associated with plasma cell dyscrasias (AL type amyloidosis) is common, but systematic description of the condition is lacking. The aim of this investigation was to characterize the clinical presentation, endoscopic findings, and histopathologic correlates in a series of patients with systemic AL amyloidosis of the luminal gastrointestinal tract. Methods: Eligible patients were identified by interrogating the histopathology database of our institution during a 14-year time period. Medical record, histopathologic, and laboratory data were collected, analyzed, and correlated with endoscopic findings. Results: Nineteen patients with systemic AL amyloidosis of the luminal gastrointestinal tract were identified. Gastrointestinal symptoms or signs related to amyloid involvement were noted in 95% of patients; abdominal pain, change in bowel habits, overt gastrointestinal bleeding, and complaints related to altered motility were the predominant presentations. Endoscopic abnormalities were found in nearly three fourths of patients, including ulcerations and submucosal hematomas. When gastrointestinal bleeding was the presenting symptom, submucosal hematomas were a common finding during endoscopic evaluation. Conclusions: AL type amyloidosis of the luminal gastrointestinal tract is a rare disease that presents with common, nonspecific complaints. The endoscopic detection of a submucosal hematoma in the setting of gastrointestinal bleeding in patients with plasma cell dyscrasias should raise suspicion for the disease.