Immunohistochemical Subtypes of Hepatocellular Adenomas in Iranian Patients: A Cross Sectional Study in a Single Center

Abstract

Background: Hepatocellular adenomas (HCAs) are rare, benign liver tumors often discovered following abdominal pain or incidentally on imaging. These tumors rarely present with bleeding or malignant changes, particularly in the inflammatory and β-catenin activated subtypes. Given the importance of identifying HCA subtypes to predict the risk of progression to malignancy, classification is necessary. Objectives: This study assessed the morphologic findings of HCAs and their correlation with immunohistochemistry analysis and radiologic data. Methods: This cross-sectional study was conducted on resection specimens and needle biopsies received in the pathology department of Imam Khomeini Hospital Complex (IKHC) over the past ten years. Twenty cases of HCAs were classified by morphology and then stained using the immunohistochemistry method for glutamine synthetase (GS), liver fatty acid-binding protein (LFABP), serum amyloid A (SAA), C-reactive protein (CRP), and β-catenin markers. The MRI findings and clinical characteristics were also recorded. Results: Based on immunohistochemistry, 11 HCAs (55%) were categorized as inflammatory type, 4 HCAs (20%) as steatotic type, 2 HCAs (10%) as β-catenin type, and 3 HCAs (15%) as unclassified type. In 13 out of 20 cases (65%), HCAs were correctly subclassified by morphology alone. Multiple masses and oral contraceptive (OCP) usage were more commonly seen in inflammatory hepatocellular adenomas (IHCAs). The number of HCAs, the presence of underlying diseases, higher Body Mass Index (BMI), and OCP usage were not statistically correlated with the subtype of HCA. Conclusions: Definite subtyping of HCAs, especially on needle biopsies, is critical as it is one of the most important factors for selecting the best treatment option. Our findings showed that morphologic diagnosis alone cannot accurately determine HCA subtypes in some cases, and using ancillary tests such as immunohistochemistry is necessary for classifying HCAs.