Non-metastatic Fibrolamellar Hepatocellular Carcinoma Presenting With Hyperammonemia: A Case Report

Abstract

A 23 year old female presented with a 2 week history of nausea, vomiting, generalized weakness, and intermittent right upper quadrant pain. Following admission, computerized tomography of abdomen revealed a large hepatic mass measuring 13 x 9 cm (figure), without evidence of metastasis. Multiple internal enhancing vessels and altered vascular architecture were visualized. Liver function tests included AST (47 U/l), ALT (41 U/l), total bilirubin (2.2 mg/dl) and INR (1.5). Patient began to show signs of altered mentation, as ammonia levels began to peak at 437 mcg/dl. A core needle biopsy confirmed Fibrolamellar hepatocellular carcinoma (FL-HCC), while pathology report revealed a 16 cm well differentiated FL-HCC without lymphovascular invasion. After the tumor was deemed unresectable the patient was listed for transplantation. The patient was placed on immunosuppression post transplantation, which included corticosteroids, mycophenolate mofetil and tacrolimus. At 1 year follow-up, the patient continues to live without recurrent disease while on sorafenib adjuvant therapy. FL-HCC is a rare hepatocellular tumor arising in non-infected, non-cirrhotic livers, accounting for 0.3% of all HCC cases. It is more frequent in young adults with no sex preponderance. Only two cases of FL-HCC accompanied by hyperammonemia due to intrahepatic shunting have been published, none of which were successfully treated. We present a rare case of FL-HCC in a patient who was comatosed from hyperammonemia and was successfully transplanted later. This case illustrates various aspects of complex management decision that includes: treatment of a patient with features of acute liver failure, management of encephalopathy, and determination of tumor resection or transplantation (LTx). The liver transplant literature on these tumors is outdated and historically, not favorable. However, systemic therapies and immunosuppressants with anti-cancer activities are now available. This patient with advanced encephalopathy was deemed unresectable and was urgently transplanted. Outcomes reported for LTx in FL-HCC are poor as the data is outdated (from 1990's). The 5-year survival rate ranged from 29% to 55%. Only two cases have been reported of FL-HCC presenting with hyperammonemia, one from the United States of America, and another from Argentina. Young patients with unresectable FL-HCC co-existing with hyperammonemia but without evidence of metastatic disease should be considered for LTx.Figure 1Figure 2