S2662 Systemic AL Amyloidosis From Plasma Cell Neoplasm in Younger Population Presenting With Gastrointestinal Symptoms Primarily

Abstract

Introduction: AL amyloidosis, known previously as primary amyloidosis, is a disorder in which fragments of monoclonal light chains deposit throughout various tissues. The incidence of amyloidosis increases after the age of 40 and a mean age of 63 years old at diagnosis. However, less than 5% of patients are diagnosed at 40 years or younger. Here we explore the case of a patient presenting with gastrointestinal symptoms diagnosed with systemic AL amyloidosis at 32 years old. Case Description/Methods: 32-year-old male presented to the emergency department with abdominal pain and hematochezia The pain was mainly in the left lower quadrant and was not associated with any nausea or vomiting. He also admitted to a 4-5 kilogram weight loss over the past year. CT abdomen and pelvis showed mild colonic wall thickening. Presumptive treatment for colitis was started but patient was not improving. Stool ova and parasites and blood cultures were negative. Biopsy specimens obtained during colonoscopy and endoscopy showed amyloidosis in the gastroesophageal junction, gastric, duodenal, terminal ileum , and colonic mucosa. Bone marrow biopsy from the right iliac showed kappa type clonal plasma cell population that made up 20-25% of marrow cellularity, consistent with plasma cell neoplasm. It was also positive for amyloid staining of small-sized blood vessels. Ultrasound-guided liver biopsy was positive for amyloidosis and fibrosis in the liver parenchyma and negative for malignancy. In summary, the test results were congruent with systemic amyloidosis involving the GI tract, liver, and multiple other organs. Discussion: AL amyloidosis, also known as systemic amyloidosis, occurs as a result of deposition of amyloid in tissue. Amyloid fibrils are composed of insoluble low molecular weight protein subunits. Deposition of amyloid into various tissues causes cellular stress and death, subversion of normal structure, organ dysfunction, and eventually death. This case illustrates the rare diagnosis of early-onset AL amyloidosis with widespread end-organ damage in multiple organ systems. It is especially important to consider both generalized symptoms, such as weight loss, as well as specific symptoms relating to end organ dysfunction, such as abdominal pain and hematochezia. GI symptoms tend to be less common, but when they are present, it may include macroglossia, dysphagia, bleeding or malabsorption. The GI tract may be involved at any level, as was the case with this patient.