Subtype, Frequency, and Associated Background Histology in Males Diagnosed with Hepatocellular Adenomas: A Single Institution Study

Abstract

Abstract Introduction/Objective Hepatocellular adenomas (HCAs) are rare, benign hepatic neoplasms arising from noncirrhotic livers, most commonly diagnosed in reproductive-age women using oral contraception with female:male ratio of 10:1. These tumors are also associated with anabolic steroid use, obesity, and diabetes. HCA subtypes and their incidence in the general population are as follows: inflammatory (HCA-I) accounting for approximately 50% of cases, HNF1A- inactivated (HCA-H) in 35-40%, β-catenin-activated (HCA-B) in 10-15%, and unclassified HCA in <5-10%. We aimed to determine HCA subtype frequency in male-only cases and their associated background liver histologies. Methods/Case Report We performed a retrospective review of all HCAs diagnosed in males from 2000–June 2022 at Mount Sinai Hospital using keywords “hepatocellular adenomas” and “hepatic adenomas;” a total of 54 cases fulfilled the criteria. Liver biopsies and resection specimens were included; duplicate cases were eliminated, and only those cases with a definitive diagnosis of HCA were included. Results (if a Case Study enter NA) There were 31 patients (age range 17-73 years) included with a total number of 41 HCAs (17 from resections and 14 from biopsies). HCA-I comprised 23/31 cases (74%), HCA-H and HCA-B each encompassed 2/31 cases (6%, respectively), one HCA-I had coexistent β-catenin mutation (3%, 1/31), and one unclassified HCA had mixed HCA-I and HCA-H features (3%, 1/31). Twelve cases were diagnosed as HCA without further subtype specification (NOS) (38%). Background liver histology was available in 24 cases. Fatty liver disease (steatosis and steatohepatitis) was found in five cases, of which four were classified as HCA-I. Of seven hepatocellular carcinomas diagnosed, four arose from NOS HCAs with either unremarkable or steatohepatitis backgrounds. Three of five HCA-I showed background nonspecific chronic hepatitis while two had glycogen storage disease. The remaining ten cases had unremarkable liver backgrounds and were found involving all HCA subtypes. Conclusion In this cohort of male-only patients, HCA-I was the most common subtype, the frequency of which is significantly higher than is reported in the general population. Only 6% of cases were HNF1A-inactivated and β- catenin-activated, far less than the reported incidence of 35-40% and 10-15%, respectively. Additionally, our findings show that the majority of HCAs had an unremarkable liver background. Further studies are necessary to determine the neoplastic drivers among male patients that develop hepatocellular adenomas.