[Focal nodular hyperplasia that was difficult to differentiate from hepatocellular carcinoma]

A 59-year-old man had received medical treatment for alcoholic hepatopathy. He stopped drinking 3 years before visiting the hospital. On medical examination, the abdominal echo showed a hepatic mass lesion that was HBs-Ag (-) and HCV-Ab (-). Computed tomography (CT) revealed a tumor of more than 25 mm in diameter at S7 of the liver. Dynamic CT showed that it was stained in the early phase but washed out in the delay phase. Magnetic resonance imaging (MRI) showed high intensity staining of the tumor in both T1-and T2-weighted images, and it was also stained in the EOB Primovist MRI hepatobiliary phase. The findings from the images were not typical for hepatocellular carcinoma(HCC) or other benign tumors. We therefore performed an S7 partial hepatectomy. We diagnosed the tumor as focal nodular hyperplasia (FNH) by histology.