BACKGROUND : Hepatic adenomas (HAs) are benign, solid liver lesions, which carry a risk of hemorrhage and malignant transformation. In this review article, we highlight advances in the diagnosis and management of HAs.

METHODS : A comprehensive review was performed utilizing MEDLINE/PubMed and Web of Science databases with a search period ending September 30, 2023. Using PubMed, the terms "hepatocellular," "hepatic," and "adenoma" were searched.

RESULTS : HA has been classified into at least eight subtypes based on molecular pathology, each exhibiting unique histopathological features, clinical considerations, and risk of malignant transformation. The most common subtype is inflammatory HA (IHA), followed by HNF1α-inactivated HA (HHA), β-catenin exon 3-mutated HA (βex3-HA), β-catenin exon 7 or 8-mutated HA (βex7,8-HA), sonic hedgehog HA (shHA), and unclassified HA. MRI is the best imaging method for diagnosis and can distinguish among HA subtypes based on fat and telangiectasia pathological characteristics. The risk of malignant transformation varies among molecular subtypes, ranging from <1% to nearly 50%. Up to 42% of HAs present with spontaneous intratumoral hemorrhage and peritoneal hemorrhage. Generally, only 15-20% of patients require surgery. HA larger than 5cm are more likely to be complicated by bleeding and malignant transformation, regardless of subtype, and should generally be resected. In particular, βex3-HA carries a high risk of malignant transformation and can be considered a true precancerous lesion.

CONCLUSIONS : The management of HAs is based on a multi-disciplinary approach. Clinical decision-making should integrate information on gender, tumor size, and HA subtyping. In the future, patients with HA will benefit from novel medical therapies tailored to the individual molecular subtypes.