ABSTRACT
Hepatocellular adenoma (HCA) is an uncommon benign hepatic tumor, and the use of oral contraceptives is known to contribute to the development of HCA. Recently, a genotype and phenotype classification system for HCA was suggested, and malignant transformation to hepatocellular carcinoma (HCC) was shown to be strongly associated with activating mutations in beta-catenin. Here, we report three cases of HCA in Korean patients: 7-cm, inflammatory and beta-catenin-activated HCA with HCC transformation in a 46-year-old man; 13-cm, beta-catenin-activated HCA with cytological atypia in a 23-year-old woman; and 10-cm, pigmented, inflammatory and beta-catenin-activated HCA in a 36-year-old man. All cases exhibited the nuclear expression of beta-catenin and diffuse cytoplasmic expression of glutamine synthetase upon immunohistochemical staining. All tumors were completely resected, and the patients were followed for 3 to 6 years with no evidence of local recurrence or metastasis.