A case of inflammatory hepatocellular adenoma associated with oral contraceptive use

Abstract

Hepatocellular adenoma is a rare tumor in Japan, but its incidence may increase in line with increased oral contraceptive use. A 32-year-old woman who had been taking oral contraceptives for about 5 years was admitted to our hospital with epigastralgia. Computed tomography and magnetic resonance imaging showed multiple hypervascular tumors, including one with a maximal diameter of 75 mm in the right lobe of the liver. She underwent surgery with a diagnosis of hepatocellular carcinoma with metastatic daughter nodules near the main tumor. Malignancy was ruled out by rapid intraoperative tissue diagnosis, and we therefore conducted only partial hepatectomy of segment 5. Histopathologic analysis confirmed inflammatory hepatocellular adenoma showing sinusoidal dilatation, peliosis, sinusoidal capillarization, unpaired arteries, and no cellular atypia. Immunohistochemistry was negative for β-catenin in the nuclei. Following the discontinuation of oral contraceptives, the remaining tumors gradually reduced in size and became unclear on T2-weighted magnetic resonance images. Immunohistochemistry was useful for determining postoperative management.