Interest of immunohistochemistry for the diagnosis of benign hepatocellular tumors

In this review, we focus on the interest of immunohistochemistry first, to differentiate the two types of benign hepatocellular nodules: focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) and second, to recognize the different subtypes of HCA: HNF1 alpha inactivated HCA, beta-catenin activated HCA and inflammatory HCA. This pathomolecular classication followed the study of genotype/phenotype correlations which led to the identification of immunohistochemical data characteristic of each subgroup. Immunohistochemical characteristics described on resected specimen are suitable on biopies of these tumors, facilitating their diagnosis and therefore allowing a better management of the patients. (C) 2010 Elsevier Masson SAS. All rights reserved.