S5628 A Silent Infiltration: Case Report of Hepatic Amyloidosis Causing Liver Failure Without Cirrhosis

Introduction: Hepatic amyloidosis is a rare but critical cause of infiltrative liver disease and non-cirrhotic portal hypertension. While it typically presents with hepatomegaly and mild to moderate transaminase elevation, progression to acute liver failure is uncommon but life-threatening. Diagnosis requires liver biopsy demonstrating amyloid deposition, confirmed by apple-green birefringence on Congo red staining under polarized light. We present a case of hepatic amyloidosis presenting as acute liver failure with encephalopathy and coagulopathy, in the absence of cirrhosis on histology. Case Description/Methods: A 47-year-old man with alcohol and tobacco use presented with abdominal distension and edema. Workup showed hyponatremia, ascites, right pleural effusion, transaminitis, direct hyperbilirubinemia, acute kidney injury, and leukocytosis. Chronic liver disease workup was overall unrevealing. Liver biopsy revealed amyloid deposition without cirrhosis; bone marrow biopsy confirmed AL amyloidosis. He began chemotherapy and plasmapheresis but developed renal failure, encephalopathy, and coagulopathy, meeting criteria for acute liver failure. He deteriorated and passed away after transition to comfort care. Discussion: AL (primary) amyloidosis is more common in womans and typically presents in the sixth to seventh decade. Hepatic involvement occurs in about 15% of cases, while the kidney is most commonly affected. Hepatic amyloidosis often presents with hepatomegaly and elevated alkaline phosphatase; hyperbilirubinemia indicates worse prognosis. Rarely, it can progress to acute liver failure with portal hypertension, especially in patients with underlying metabolic dysfunction-associated steatotic liver disease or cirrhosis, complicating diagnosis and management. Untreated hepatic AL amyloidosis has a median survival of 8–9 months. It is essential to include amyloidosis in the differential for conjugated hyperbilirubinemia when viral, autoimmune, and cholestatic workup is negative. Imaging may reveal diffusely decreased hepatic attenuation, triangular hepatomegaly, and signs of portal hypertension. However, imaging is not diagnostic. Confirmation requires liver biopsy showing amyloid with apple-green birefringence on Congo red staining. Management includes supportive care for acute liver failure such as hepatic encephalopathy, clinically significant coagulopathy, management of sequelae of portal hypertension such as variceal bleeds or ascites, and initiation of chemotherapy targeting the plasma cell dyscrasia.