β-Catenin activated hepatocellular adenoma: a report of three cases in Korea

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 β-catenin. Here, we report three cases of HCA in Korean patients: 7-cm, inflammatory and β-catenin-activated HCA with HCC transformation in a 46-year-old man; 13-cm, β-catenin-activated HCA with cytological atypia in a 23-year-old woman; and 10-cm, pigmented, inflammatory and β-catenin-activated HCA in a 36-year-old man. All cases exhibited the nuclear expression of β-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.