Hepatocellular Adenomas: WHO Classification and Immunohistochemical Workup

This review discusses the various subtypes of hepatocellular adenomas (HCAs), their diagnosis, and management. HCAs are benign tumors, mostly seen in young women in a normal background liver. Recent advances in understanding HCA pathogenesis and molecular alterations led to recognition of different subtypes, now included in the WHO classification. Complications include hemorrhage and rarely malignant transformation into hepatocellular carcinoma. Diagnosis and differentiation are challenging, requiring careful attention to clinical setting, histology, and immuostaining profile. Risk of complications varies depending on the HCA; hence, subtyping has clinical significance and is performed based on morphology and use of selected immunohistochemical markers.