Hepatology: Atypical images for multiple focal nodular hyperplasia a


Figure 1 Magnetic resonance imaging (MRI) findings of the liver.

Case report A 32-year-old woman presented after abnormalities in biliary enzyme levels had been identified on a routine medical check-up. She had experienced no clinical symptoms and had no specific past history. She had not been taking any medications, including supplements and oral contraceptives. Her history of alcohol intake was 8 g/day of ethanol over the previous 10 years. Laboratory evaluation revealed: aspartate aminotransferase, 23 IU/L; alanine aminotransferase, 27 IU/L; gamma glutamyltranspeptidase, 156 IU/L; and alkaline phosphatase, 363 IU/L. Negative results were obtained for hepatitis B surface antigen and hepatitis C virus antibody, and also for antinuclear antibody, anti-mitochondrial antibody, and M2. Levels of alpha fetoprotein and des-γ-carboxy prothrombin were within normal limits. Enhanced CT shows that the larger masses had the central scar-like structure, while other masses showed diffuse enhancement. Magnetic resonance imaging (MRI) showed all masses were iso- to hypointense on fat-suppressed T1-weighted imaging and hyper- to isointense on T2-weighted imaging. The center of the largest mass is widely hypointense on unenhanced fat-suppressed T1-weighted imaging, it seems to represent necrosis. However, contrast-enhanced MRI revealed the largest mass as enhanced except for the central scar-like structure in the early phase, and washed out in the late phase. (Fig. 1a–b). These diagnostic images suggested atypical hepatic tumors such as primary hepatic tumors or metastatic tumors, so liver biopsy was performed. The specimens contained fibrous proliferation,

Figure 2 Histological findings of the tumor.

malformed vessels, cholangiolar proliferation, and various inflammatory infiltrates consistent with FNH (Fig. 2). Based on these results, FNH was diagnosed. No change in tumor size and shape or radiographic findings has been seen on follow-up examination after 1 year. FNH is an uncommon benign lesion that usually presents as a solitary nodule. Morphologically, FNH may show lobulated margins and a central scar. MRI shows typical FNH as iso- to hypointense on T1-weighted imaging and slightly hyper- to isointense on T2-weighted imaging. FNH shows intense homogeneous enhancement in the arterial phase and enhancement of the central scar in the late phase. The nodules in this case were atypical for FNH because they were multiple (eight) lesions with differing radiographic findings in each mass. The imaging pattern on the MRI was compatible with FNH. MRI showed the larger masses with central scar-like structures, but the other masses had no central scar-like structure. The center of the largest mass was slightly enhanced with rapid wash-out in late phase. These findings suggested necrosis rather than scar, representing an atypical finding for FNH. Biopsy was therefore performed. Histological examination revealed fibrous proliferation, malformed vessels, cholangiolar proliferation, and various inflammatory infiltrates. Based on these findings, multiple FNH was diagnosed. FNH is a benign lesion that follows a benign course. Conservative treatment is therefore recommended for FNH and surgical intervention is not considered necessary. In conclusion, we present a case of multiple FNH with atypical imaging characteristics. FNH does not require surgical intervention. The possibility of atypical cases should be considered when making a preoperative diagnosis. Contributed by N Yoshizawa, MD,* H Fuke, MD,* A Hashimoto, MD,* A Shimizu, MD,* K Sugimoto, MD,† K Shiraki, MD,† S Isaji, MD‡ *Internal Medicine, Saiseikai Matsusaka General Hospital, Matsusaka, Japan and †The First Department of Internal Medicine, ‡The First Department of Surgery, Mie University School of Medicine, Mie, Japan

Journal of Gastroenterology and Hepatology 30 (2015) 969 © 2015 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd


Hepatology: Atypical images for multiple focal nodular hyperplasia.

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