title: Hepatocellular adenomas in a large community population, 2000 to 2010: reclassification per current World Health Organization classification and results of long-term follow-up.
abstract: The data used for the World Health Organization classification of hepatocellular adenoma (HCA) is largely based on cases from tertiary level centers in Europe. This study examines the distribution of HCA subtypes in a large community population and determines the impact of immunohistochemistry (IHC) on reclassification, diagnosis, and management. All cases diagnosed as HCA in a large community hospital network from 2000 to 2010 were reviewed. The following immunohistochemical stains were evaluated in cases where paraffin-embedded tissue was available (n = 35): β-catenin, glutamine synthetase, serum amyloid A, C-reactive protein, liver fatty acid binding protein. Twenty-eight of 35 cases were confirmed to be HCA, 5 cases were reclassified as well-differentiated hepatocellular carcinoma, and 2 cases were reclassified as focal nodular hyperplasia. The HCA cases were further subclassified into hepatocyte nuclear factor 1α inactivated (29%), inflammatory (32%), inflammatory with β-catenin activation (3%), noninflammatory β-catenin activated (0%), and unclassified (36%). Long-term follow-up was available on 33 of 35 cases, and there were no cases of recurrence or distant metastasis. IHC can provide a definite HCA subtype in two-thirds of cases. HCA subtypes in this large community-based population differed from the prior large French studies, in that there were a greater proportion of unclassified adenomas and a virtual absence of β-catenin-activated adenomas. It is likely that most β-catenin-activated hepatocellular tumors show morphologic and reticulin staining abnormalities indicative of well-differentiated hepatocellular carcinoma. IHC for glutamine synthetase and serum amyloid A can identify cases with β-catenin activation and aid in the distinction of inflammatory adenoma and focal nodular hyperplasia.
authors.affiliation: Department of Pathology, Woodland Hills Medical Center, Southern California Permanente Medical Group, CA 91367. Electronic address: nafis.x.shafizadeh@kp.org.
authors.forename: Nafis
authors.initials: N
authors.lastname: Shafizadeh
authors.affiliation: Department of Anatomic Pathology, University of California, San Francisco, San Francisco, CA 94143.
authors.forename: Gillian
authors.initials: G
authors.lastname: Genrich
authors.affiliation: Department of Anatomic Pathology, University of California, San Francisco, San Francisco, CA 94143.
authors.forename: Linda
authors.initials: L
authors.lastname: Ferrell
authors.affiliation: Department of Anatomic Pathology, San Francisco Veterans Affairs Medical Center, University of California, San Francisco, San Francisco, CA 94121.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Kakar
mesh_terms: D018248:Adenoma, Liver Cell / Q000145:classification / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D002140:California; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D020518:Focal Nodular Hyperplasia / Q000175:diagnosis / Q000473:pathology; D005500:Follow-Up Studies; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D051538:Hepatocyte Nuclear Factor 1-alpha / Q000235:genetics / Q000378:metabolism; D006764:Hospitals, Community; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation / Q000473:pathology; D008113:Liver Neoplasms / Q000145:classification / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D014944:World Health Organization; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D051538:Hepatocyte Nuclear Factor 1-alpha; D051176:beta Catenin; D005974:Glutamate-Ammonia Ligase
keywords: HNF1α; Hepatocellular adenoma; Immunohistochemistry; Inflammatory; β-catenin