A Case of Hepatic Anisakiasis

Abstract

A 64-year-old man with hypertension and angina was detected with a hepatic tumor by abdominal computed tomography (CT). Laboratory data revealed no apparent abnormalities ; however, serological test results were positive for hepatitis B surface antigen. Dynamic CT revealed low-density mass measuring 2 cm in diameter in Couinaud segment 8 with peripheral enhancement. Magnetic resonance imaging showed different signal intensities at the center and periphery of the mass in the hepatic phase enhancement with gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid, and diffusion-weighted imaging showed a high-intensity area. Hepatic resection of segment 8 was performed after the patient was diagnosed with intrahepatic cholangiocarcinoma while considering a differential diagnosis of sclerosing hepatic carcinoma or inflammatory pseudotumor. Intraoperatively, the mass was identified as a reddish, slightly bulging mass on the surface of the liver, which was a well-defined, whitish nodule with irregular shape on a cut surface. Histologically, it consisted of palisading granuloma surrounded by predominantly eosinophilic infiltration. Dead Anisakis larvae were detected in the necrotic area. Finally, the patient was diagnosed with hepatic anisakiasis.