title: Pigmented hepatocellular adenoma with β-catenin activation: case report and literature review.
abstract: Hepatocellular adenomas (HCAs) are benign liver tumors recently characterized into 4 different types according to genetic, pathological and clinical features. The prognosis is not well established yet and malignant transformation has been recently associated with β-catenin activation. We aimed to describe a case of a pigmented HCA with β-catenin nuclear expression and inflammatory features and to review the cases of pigmented HCAs in the literature. We report a case of a young female patient without contraceptive use, with a liver tumor diagnosis. Liver biopsy revealed diffuse expression of β-catenin and a partial hepatic resection was performed. The histologic analysis revealed a hepatocellular tumor composed of uniform trabeculae of hepatocytes and solid areas, the later with a significant amount of black pigment highlighted by Masson-Fontana stain. Immunohistochemistry showed co-expression of C-reactive protein and serum amyloid A in the tumor. Literature review revealed that pigmented HCAs, previously reported as dark adenomas, are rare tumors. In HCAs, the presence of β-catenin activation should be searched for due to the higher risk of malignant transformation in hepatocarcinoma. We describe a pigmented HCA with β-catenin nuclear expression and inflammatory features being the fifth case reported so far.
authors.affiliation: Gastroenterology Department, Centro Hospitalar São João, Porto. Portugal.
authors.forename: Rosa
authors.initials: R
authors.lastname: Coelho
authors.affiliation: Gastroenterology Department, Centro Hospitalar São João, Porto. Portugal.
authors.forename: Regina
authors.initials: R
authors.lastname: Gonçalves
authors.affiliation: Pathology Department, Centro Hospitalar São João, Porto. Portugal; IPATIMUP, Institute of Molecular Pathology and Immunology of the University of Porto, Porto. Portugal.
authors.forename: Fátima
authors.initials: F
authors.lastname: Carneiro
authors.affiliation: Pathology Department, Centro Hospitalar São João, Porto. Portugal.
authors.forename: Margarida
authors.initials: M
authors.lastname: Fernandes
authors.affiliation: Pathology Department, Centro Hospitalar São João, Porto. Portugal.
authors.forename: Joanne
authors.initials: J
authors.lastname: Lopes
authors.affiliation: Pathology Department, Centro Hospitalar São João, Porto. Portugal.
authors.forename: Susana
authors.initials: S
authors.lastname: Guimarães
authors.affiliation: Gastroenterology Department, Centro Hospitalar São João, Porto. Portugal.
authors.forename: Guilherme
authors.initials: G
authors.lastname: Macedo
mesh_terms: D018248:Adenoma, Liver Cell / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D000328:Adult; D002097:C-Reactive Protein / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D008279:Magnetic Resonance Imaging; D010858:Pigmentation; D012835:Silver Nitrate; D014057:Tomography, X-Ray Computed; D051176:beta Catenin / Q000378:metabolism*
chemical_list: C051037:Fontana-Masson stain; D051176:beta Catenin; D002097:C-Reactive Protein; D012835:Silver Nitrate