Retrospective study of hepatocellular adenomas based on the phenotypic classification system: A report from China

A molecular and pathological classification system for hepatocellular adenomas (HCAs) was recently introduced in Europe, resulting in four major identified subgroups. Asian countries have a considerably lower incidence of HCA as well as a different etiology. We aimed to characterize HCAs in a Chinese population based on this new classification system. A series of 30 patients with HCA were analyzed based on the phenotypic classification system using immunohistochemical analysis. Investigated antigens included liver-fatty acid binding protein (L-FABP), glutamine synthetase (GS), β-catenin, serum amyloid A (SAA), and C-reactive protein (CRP). Of the 30 cases (20 female) included in this study, only one had a history of oral contraceptive use. We identified 9 (30%) hepatocyte nuclear factor (HNF)-1α-inactivated HCAs, 3 (10%) β-catenin-activated HCAs, 11 (36.7%) inflammatory HCAs, and 7 (23.3%) unclassified HCAs. In the inflammatory HCA group, 2 cases demonstrated concurrent β-catenin-activation. Homogeneous steatosis (6/9) and microadenomas (2/9) were more frequently observed in HNF1α-inactivated HCAs. A body mass index (BMI) of greater than 25 (5/11), alcohol use (4/11), and steatosis in background liver (3/11) were more frequent in inflammatory HCAs. β-catenin-activated HCAs were larger than those of other subgroups. Despite obvious differences in etiology and gender proportion compared with Western countries, the clinical and pathological characteristics of HCA subgroups in China are similar to those in Europe. The phenotypic classification system could be reliably applied to Chinese patients as a meaningful tool for HCA management.