A Resected Case of Focal Nodular Hyperplasia

We report a case of resected focal nodular hyperplasia (FNH), a tumor-like lesion of the liver. The patient was a 24-year-old woman. Ultrasonography (US) of the abdomen revealed a mass in the liver. US revealeda hypoechoic lesion in the lateral segment, and dynamic computed tomography showed a high density area in the arterial phase and a low density area in the portal phase. Angiography of the liver showed a hypervascular area accompanied by radially running abnormal vessels from the center of the tumor. Therefore FNH was suspected, but hepatocellular carcinoma could not be denied, and lobectomy of the left lobe of the liver was performed in September 1990. A diagnosis of FHN was finally made on the basis of histopathological examination combined with clinical data. FNH has been considered relatively rare, but reported cases have increased recently. We collected data on 30 cases including ours recently published in Japan and focused especially on the preoperative diagnosis.