title: Non-Epstein-Barr virus associated lymphoepithelioma-like carcinoma of the inferior common bile duct.
abstract: A carcinoma displaying undifferentiated features with dense lymphoplasmacytic infiltration is defined as a lymphoepithelioma-like carcinoma (LEC), and some of LEC is associated with Epstein-Barr virus (EBV). All of the 13 previously reported cases of LEC of the biliary system were intrahepatic in location. Herein, we describe the first case of LEC of the inferior common bile duct. A 68-year-old Japanese man, who had been previously treated for hepatocellular carcinoma using microwave coagulation therapy, was found to have tumors of the common bile duct and pancreas head. Histopathological study of the resected tumor showed solid or cohesive nests of large undifferentiated cells with irregular large vesicular nuclei and nucleoli. Around the tumor cell nests, dense lymphoplasmacytic infiltration was observed. Focal glandular differentiation (approximately 5%) was also present. These histopathological features corresponded morphologically to LEC. Immunohistochemically, the tumor cells were positive for cytokeratin (CK) 7, CK 19 and CA19-9, but negative for CK 20 and Hep Par 1. In situ hybridization for Epstein Barr virus early small RNAs disclosed no nuclear signal in tumor cells. Therefore, a diagnosis of non-EBV-associated LEC of the inferior common bile duct was made. Although the prognosis of the biliary LEC is thought to be better than that of conventional cholangiocarcinoma, the differences in prognosis between EBV-positive and -negative cases have not yet been established. Therefore, additional case studies will be needed to clarify the clinicopathological features of LEC of the biliary tract.
authors.affiliation: Mitsuaki Ishida, Fumiyoshi Kojima, Machiko Hotta, Hidetoshi Okabe, Department of Clinical Laboratory Medicine and Division of Diagnostic Pathology, Shiga University of Medical Science, Otsu, Shiga, 520-2192, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Ishida
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Mori
authors.forename: Hisanori
authors.initials: H
authors.lastname: Shiomi
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Naka
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Tsujikawa
authors.forename: Akira
authors.initials: A
authors.lastname: Andoh
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Saito
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Kurumi
authors.forename: Fumiyoshi
authors.initials: F
authors.lastname: Kojima
authors.forename: Machiko
authors.initials: M
authors.lastname: Hotta
authors.forename: Tohru
authors.initials: T
authors.lastname: Tani
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Fujiyama
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Okabe