Molecular classification of hepatocellular adenomas: impact on clinical practice.

Hepatocellular adenomas are rare benign liver tumors usually developing in young women using oral contraception. The two main complications are hemorrhage (10-20%) and malignant transformation into hepatocellular carcinoma (<5%). A molecular classification has been recently updated in six major subgroups, linked to risk factors, histology, imaging and clinical features: adenomas inactivated for HNF1A , inflammatory adenomas, β-catenin-activated adenomas mutated in exon 3, β-catenin-activated adenomas mutated in exon 7-8, sonic hedgehog adenomas, and unclassified adenomas. Indeed, β-catenin-mutated adenomas in exon 3 are associated with malignant transformation, and sonic hedgehog adenomas with bleeding. This new nosology of hepatocellular adenomas will help to stratify patients according to risk of complications and will guide therapeutics in the future.