2621 Gastrointestinal and Hepatic Amyloidosis: An Unusual Cause for Abdominal Pain and Elevated Liver Enzymes

Abstract

INTRODUCTION: Amyloidosis is a complex, multi-system disorder involving the extracellular deposition of insoluble protein fragments. Symptomatic gastrointestinal and hepatic involvement are relatively rare, often leading to a challenging and delayed diagnosis. CASE DESCRIPTION/METHODS: We describe a case of gastroduodenal and hepatic amyloidosis in a 61-year-old male with a history of plasma cell myeloma with systemic AL (amyloid light chain) amyloidosis with cardiac involvement who presented with 3 months of epigastric pain associated with nausea, vomiting, and 20-pound weight loss. Laboratory testing revealed transaminitis including a significantly elevated alkaline phosphatase (ALP). Right upper quadrant ultrasound was normal. Computed tomography (CT) showed diffuse mesenteric haziness and heterogenous edematous appearance of the liver. Since his diagnosis of amyloidosis, the patient had been treated with cyclophosphamide, bortezomib, and dexamethasone (CyBorD) therapy with appropriate light chain suppression. Despite treatment, he continued to have persistent gastrointestinal symptoms. He therefore underwent upper endoscopy with biopsies of the esophagus, stomach and small intestine notable for positive Congo red staining, with classic green birefringence under polarized light, indicating extensive amyloid deposition within the lamina propria. Subsequent transjugular liver biopsy demonstrated marked centrilobular sinusoidal dilation and increased fibrosis with amyloid deposition within the vessels of the portal tract. His symptoms were medically managed, and he was continued on chemotherapy while undergoing evaluation for cardiac transplant prior to consideration for autologous stem cell transplant. DISCUSSION: Gastrointestinal and hepatic amyloidosis are unusual diagnoses that present with variable and nonspecific symptoms, and often late in the disease course. Clinicians should maintain a high index of suspicion of amyloidosis in patients with previously diagnosed plasma cell or inflammatory disease. Our case demonstrates that despite high-dose chemotherapy, patients may develop refractory disease with multi-organ involvement. Prognosis depends on the amyloid subtype, and whether there is gastrointestinal infiltration as these patients typically have worse outcomes, emphasizing the importance of prompt diagnosis. Management aims to treat the underlying amyloid type of pathology, with supportive therapy to alleviate the specific gastrointestinal symptoms.