Improvements in understanding the pathophysiology of the different benign liver nodules have refined their nosological classification. New criteria have been identified using imaging, histology and molecular analyses for a precise diagnosis of these tumours. Improvement in the classification of liver tumours provides a more accurate prediction of disease progression and has modified patient management. Haemangioma and focal nodular hyperplasia, the most common benign liver tumours that develop in the absence of chronic liver disease, are usually easy to diagnose on imaging and do not require specific treatment. However, hepatocellular adenomas and cirrhotic macronodules can be difficult to discriminate from hepatocellular carcinoma. The molecular subtyping of hepatocellular adenomas in five major subgroups defined by HNF1A inactivation, β-catenin mutation in exon 3 or exon 7/8, and activation of inflammatory or Hedgehog pathways helps to identify the tumours at risk of malignant transformation or bleeding. New clinical, biological and molecular tools have gradually been included in diagnostic and treatment algorithms to classify benign liver tumours and improve patient management. This Review aims to explain the main pathogenic mechanisms of benign liver tumours and how this knowledge could influence clinical practice.

对不同良性肝结节的病理生理学的理解的改进改进了它们的疾病分类。已经使用成像、组织学和分子分析确定了新标准，以精确诊断这些肿瘤。肝脏肿瘤分类的改进提供了更准确的疾病进展预测，并改进了患者管理。血管瘤和局灶性结节性增生是在没有慢性肝病的情况下发生的最常见的良性肝脏肿瘤，通常很容易通过影像学诊断，不需要特殊治疗。然而，肝细胞腺瘤和肝硬化大结节很难与肝细胞癌区分开来。由HNF1A定义的五个主要亚组中肝细胞腺瘤的分子亚型失活、外显子 3 或外显子 7/8 中的 β-catenin 突变以及炎症或 Hedgehog 通路的激活有助于识别有恶变或出血风险的肿瘤。新的临床、生物和分子工具已逐渐纳入诊断和治疗算法，以对良性肝脏肿瘤进行分类并改善患者管理。本综述旨在解释良性肝肿瘤的主要致病机制以及这些知识如何影响临床实践。