title: Benign hepatocellular nodules: what have we learned using the patho-molecular classification.
abstract: Focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) are benign hepatocellular tumors that develop most frequently in females and in non-cirrhotic livers. HCA are prone to bleed and to transform into hepatocellular carcinoma (HCC). Four major subgroups of HCA have been thus far identified: HNF1α mutated HCA, inflammatory HCA (IHCA), β-catenin mutated HCA (b-HCA and b-IHCA), based on mutations in specific oncogenes and tumor suppressors. B-HCA and b-IHCA are strongly associated with HCC transformation. Benign hepatocellular tumors can be classified using immunohistochemistry (LFABP, CRP, GS, b-catenin). Analysis of HCA phenotypes has led to the identification of patients at risk of HCC transformation and therefore improved the indications provided by invasive and non-invasive diagnostic techniques, such as biopsies and MRI. These recent advances have broadened the clinical scope of HCA in various conditions, such as their presence in males, in obese patients, in patients suffering from liver vascular disorders, genetic diseases. However, specific immunohistochemistry has shown limitations particularly for the identification of b-HCA, thereby, outlining the importance of molecular studies to improve the diagnosis/prognosis of HCA. If evaluation of prognosis and treatment has benefited from these advances, much more needs to be done to obtain guidelines for good clinical practice.
authors.affiliation: Service d'Anatomie Pathologique, Cliniques universitaires Saint-Luc, Université catholique de Louvain, 1200 Brussels, Belgium. christine.sempoux@uclouvain.be
authors.forename: Christine
authors.initials: C
authors.lastname: Sempoux
authors.forename: Charissa
authors.initials: C
authors.lastname: Chang
authors.forename: Annette
authors.initials: A
authors.lastname: Gouw
authors.forename: Laurence
authors.initials: L
authors.lastname: Chiche
authors.forename: Jessica
authors.initials: J
authors.lastname: Zucman-Rossi
authors.forename: Charles
authors.initials: C
authors.lastname: Balabaud
authors.forename: Paulette
authors.initials: P
authors.lastname: Bioulac-Sage
mesh_terms: D018248:Adenoma, Liver Cell / Q000145:classification* / Q000473:pathology*; D006801:Humans