Fibrolamellar Hepatocellular Carcinoma

Abstract

Fibrolamellar hepatocellular carcinoma (FLM) is a rare tumor that occurs in young adults. It occurs in the absence of chronic liver disease or cirrhosis. Serum alpha-fetoprotein is typically normal. FLM is characterized by a triad of morphological features: polygonal tumour cells with eosinophilic cytoplasm, prominent nucleoli and lamellar pattern of fibrosis. A central scar is seen in some cases. FLM has to be distinguished from conventional hepatocellular carcinoma (HCC). Scirrhous variant of HCC can closely resemble FLM, but lacks its typical cytological features. Acinar differentiation and focal mucin production can be seen in FLM and can be confused with adenocarcinoma. Focal neuroendocrine differentiation occurs in a minority of FLMs and can be mistaken for neuroendocrine tumours. Some of the molecular changes typically observed in conventional HCC like p53 and beta-catenin mutations are not observed in FLM. FLM is an aggressive neoplasm with 5-year survival of around 50%. Although the prognosis in FLM has been described as favorable compared to conventional HCC, this is likely to be related to absence of cirrhosis rather than unique morphological features of the tumor.KeywordsEpidermal Growth Factor ReceptorFocal Nodular HyperplasiaCentral ScarNoncirrhotic LiverUnique Morphological FeatureThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.