A case of intrahepatic mass-forming portal biliopathy mimicking intrahepatic cholangiocarcinoma

A 75-year-old man was referred to our department because of an enlarging intrahepatic mass detected on magnetic resonance imaging (MRI) follow-up for another disease. MRI showed hypointensity on T1-weighted imaging and hyperintensity on T2-weighted imaging in liver segment 4. Abdominal plain computed tomography (CT) indicated a low-density lesion with an unclear boundary, measuring approximately 4 cm × 3 cm in liver segment 4. Dynamic CT showed early rim enhancement and gradual central enhancement. Contrast-enhanced CT also showed occlusion of the portal vein in segment 4. As the possibility of intrahepatic cholangiocarcinoma could not be excluded on imaging studies, we performed laparoscopic left medial sectionectomy. Histologically, the lesion showed diminished numbers of hepatocytes with increased collagen fibers compared with normal, with no patent portal vein. We considered this lesion a reactive lesion caused by collapse of the liver parenchyma owing to localized obstruction and loss of the portal vein. This lesion was pathologically diagnosed as portal biliopathy. We experienced an extremely rare case of intrahepatic mass-forming portal biliopathy that mimicked a hepatic tumor, which was diagnosed by laparoscopic resection. Portal biliopathy rarely forms intrahepatic mass lesions and must be distinguished from a malignant hepatic tumor.