S5885 Multisystem Amyloidosis Mimicking Cirrhosis and Hepatorenal Syndrome

Introduction: Hepatic involvement in systemic amyloidosis is rare but can closely resemble advanced liver disease. Nonspecific presentations often lead to diagnostic delays, particularly in patients with coexisting plasma cell dyscrasias. We present a case of hepatic amyloidosis initially misdiagnosed as cirrhosis with hepatorenal syndrome (HRS). Case Description/Methods: A 78-year-old woman with atrial fibrillation and smoldering IgG lambda myeloma (diagnosed 3 months prior - 13% plasma cells, negative bone marrow Congo red) presented with progressive abdominal distention, 40-lb unintentional weight loss, jaundice, dyspnea, and edema. Exam revealed icterus, digital clubbing, anasarca and hepatosplenomegaly. Labs showed hyponatremia, metabolic acidosis, renal dysfunction, cholestatic liver injury (total bilirubin 9.9 mg/dL, alkaline phosphatase 1311 U/L), and elevated BNP (3774 pg/mL). Right upper quadrant Doppler showed cirrhotic morphology without portal vein thrombosis. Computed tomography abdomen showed hepatomegaly, ascites, gallbladder wall and mesenteric edema, and volume overload. Hepatobiliary scan was negative. Magnetic resonance cholangiopancreatography (MRCP) showed no obstruction but revealed diffuse hepatic parenchymal signal loss, suggesting infiltrative disease as cause of liver injury. Echocardiography revealed left ventricular ejection fraction 45%–50% with grade III diastolic dysfunction; cardiac magnetic resonance imaging (MRI) showed late gadolinium enhancement consistent with infiltrative cardiomyopathy. Given her myeloma and multiorgan involvement, systemic amyloidosis was suspected. Despite initial negative bone marrow Congo red staining, fat pad biopsy confirmed AL amyloidosis. Her condition deteriorated with refractory hypotension and multiorgan failure. Patient transitioned to comfort care. Discussion: This case highlights the diagnostic challenge of hepatic amyloidosis, which can mimic cirrhosis and HRS. Initial tests, including bone marrow biopsy, may be falsely negative due to the sequential pattern of amyloid deposition, often beginning in soft tissues like fat pad before involving deeper organs. Multi-organ dysfunction, particularly with restrictive cardiomyopathy and cholestatic liver injury in the absence of classic cirrhosis risk factors, should prompt consideration of infiltrative diseases. MRCP and cardiac MRI can provide valuable diagnostic clues, while fat pad biopsy remains a minimally invasive and highly specific tool for diagnosis. Early recognition is crucial, as systemic amyloidosis can progress rapidly, limiting treatment options and worsening prognosis.