Navigating hyperammonemic encephalopathy: Continuous renal replacement therapy in a urea cycle defect secondary to fibrolamellar hepatocellular carcinoma

Fibrolamellar hepatocellular carcinoma (FL-HCC) is a rare liver cancer variant, accounting for less than 1% of primary hepatic malignancies, predominantly affecting young adults. This case report presents a 24-year-old patient with altered mental status, ultimately diagnosed with metastatic FL-HCC and secondary hyperammonemic encephalopathy, a rare but critical complication. Management involved continuous renal replacement therapy (CRRT), ammonia-scavenging agents, and targeted radiotherapy for the primary tumor. This report elucidates the clinical presentation of FL-HCC, explores the pathophysiology of hyperammonemia-induced encephalopathy, and discusses management strategies, emphasizing the therapeutic role of dialysis modalities.