A Case of Focal Nodular Hyperplasia Difficult to Diagnose Preoperatively

Susumu Shibasaki, Hideki Yokoo, Toshiya Kamiyama, Kazuaki Nakanishi, Munenori Tahara, Daisuke Fukumori, Akihiro Usui, Michiaki Matsushita and Satoru Todo

Department of General Surgery, Hokkaido University, Graduate School of Medicine

Focal nodular hyperplasia (FNH) may be difficult to differentiate from hepatocellular carcinoma (HCC). We report a case of FNH with unusual MRI and Sonazoid US fingings. A 41-year-old woman with hepatitis B virus and suffering from epigastralgia was found to have serum liver function test and tumor marker results within normal limits. Contrast-enhanced computed tomography (CT) showed a 3 cm high-density area with a central nonenhanced lesion having a central scar-like center in segment 1. Sonazoid US showed a 'spoke wheel sign' in the early vascular phase, but a defect in the postvascular phase. Superparamagnetic iron oxide MRI showed decreasing uptake. Due to the possibility of HCC, we conducted a hepatic caudate lobectomy. The pathological examination indicated FNH. Given that Kupffer cells are not reflected in some image findings, it is important to conduct a microscopic diagnosis, including resection, to definitively rule out FNH.

Key words
focal nodular hyperplasia (FNH), hepatocellular carcinoma (HCC), Kupffer cell

Reprint requests
Susumu Shibasaki Department of General Surgery, Hokkaido University, Graduate School of Medicine
N-15 W-7 Kita-Ku, Sapporo, 060-8638 JAPAN

Accepted
March 26, 2008

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