The value of immunophenotyping hepatocellular adenomas: consecutive resections at one UK centre

Aims: To determine the utility of immunophenotyping for classification of hepatocellular adenomas resected at one Scottish centre. Methods and results: This study comprised a retrospective review and immunophenotyping of consecutive resected benign hepatocellular tumours. Fifty‐five patients (seven men) had 64 adenomas and 26 focal nodular hyperplasias (FNHs) resected. Map‐like glutamine synthetase (GS) staining was specific for FNH. Immunophenotyping changed the morphological typing for three adenomas and resolved 16 of 18 unclassified or equivocal cases, revealing GS positivity in these (seven) and four others. Steatotic/liver fatty acid binding protein‐deficient adenomas were the commonest type in women (12/29 women, 41%) but were absent from men. Where one of multiple adenomas was morphologically unclassified, there was still a shared immunophenotype. Diffuse CD34 positivity correlated with GS positivity or unclassified status (P