Lymphoepithelioma-like cholangiocarcinoma: a mimic of hepatocellular carcinoma on imaging features.

Primary lymphoepithelioma-like carcinoma in the liver is extremely rare. A few cases of lymphoepithelioma-like cholangiocarcinoma have been reported, but few radiologic features were described. We reviewed 23 cases of lymphoepithelioma-like cholangiocarcinoma reported between 1996 and 2014 and describe a rare case of a 35-year-old woman in our hospital who was diagnosed with lymphoepithelioma-like cholangiocarcinoma of the liver and was a hepatitis B carrier. The tumor (1.6 cm) in our patient appeared to be hypoechoic in sonographic images and hypodense in computed tomography (CT) images. In addition, it was homogeneous hypointense in T1-weighted magnetic resonance (MR) images (MRI) and hyperintense in T2-weighted MRI. Dynamic gadolinium-enhanced MRI showed typical image pattern of hepatocellular carcinoma (HCC). The patient underwent a laparoscopic left hepatic lobectomy, and the resected tumor consisted of well-differentiated glandular cells with extensive lymphocytic infiltration that were immunoreactive to CK (AE1/AE3), CD3, and CD20. In addition, the tumor was positive for Epstein-Barr virus-encoded RNA in situ hybridization. Finally, lymphoepithelioma-like cholangiocarcinoma was diagnosed. In previous studies, the incidence is highest among middle-aged people. Most tumors appeared to be hypodense with either hypovascular or hypervascular patterns in CT images. This case report is the first study to address sonography, CT, and MRI observations and delineate pathologic correlations. We suggest that the imaging pattern of lymphoepithelioma-like cholangiocarcinoma, either the typical cholangiocarcinoma pattern or a mimic of HCC, should be considered in the differential lists for HCC.