Molecular classification of hepatocellular adenoma in clinical practice.

Hepatocellular adenomas (HCA) are rare benign liver tumors occurring in young women taking contraception. They are associated with rare complications such as bleeding or malignant transformation into hepatocellular carcinoma. A molecular classification has divided HCA in several subgroups linked with risk factors, clinical behaviour, histological features and imaging: HNF1A inactivated HCA, Inflammatory HCA, CTNNB1 mutated HCA in exon 3, CTNNB1 mutated in exon 7 and 8 HCA, sonic hedgehog HCA and unclassified HCA. CTNNB1 mutated HCA in exon 3 and sonic hedgehog HCA have been linked with a high risk of malignant transformation and bleeding respectively. Herein, we review how molecular classification has modified our understanding of the pathophysiology and risk factors of HCA development, analysing its impact on clinical care in the field of diagnosis and therapeutic stratification.