Hilar cholangiocarcinoma represent the majority of cholangiocarcinoma, accounting for 40-60% of whole cases. Complete resection remains the most effective and only potentially curative therapy for cholangiocarcinoma. Important factors for resection of cholangiocarcinoma such as diagnostic methods and clinical staging has been improved. Cancer staging system should be useful for guiding treatment and predicting the chance of survival. After Bismuth-Corlette classification was reported, several staging systems has been proposed and updated to accomplish this purpose. Currently 6th ed. American Joint Committee on Cancer (AJCC) staging, 2nd ed. Japanese Society of Biliary Surgery (JSBS) classification and modified Memorial Sloan-Kettering Cancer Center (MSKCC) classification are used worldwide for staging of hilar cholangiocarcinoma. These systems consider not only the tumor extent but also local biological factors that affect the resectability, but the priority among them has not yet been evaluated and randomized studies are being expected to verify this.
Bile Duct Neoplasms/classification/*pathology ; *Bile Ducts, Intrahepatic ; Cholangiocarcinoma/classification/*pathology/secondary ; Humans ; Neoplasm Staging

OBJECTIVETo compare the immunoprofiles of intrahepatic cholangiocarcinoma and metastatic colorectal adenocarcinoma for mucin glycoproteins (including MUC1, MUC2, MUC5AC and MUC6) and cytokeratins (including CK7, CK19 and CK20), and to assess their diagnostic value.

METHODSOne hundred cases of intrahepatic cholangiocarcinoma and 21 cases of metastatic colorectal adenocarcinoma were enrolled into the study. Immunohistochemical study for MUC1, MUC2, MUC5AC, MUC6, CK7, CK19 and CK20 was carried out in all cases by EnVision method.

RESULTSIn intrahepatic cholangiocarcinoma, the expression rates of MUC1, MUC2, MUC5AC and MUC6 were 61.0%, 2.0%, 22.0% and 8.0% respectively, as compared to 57.1%, 47.6%, 19.0% and 23.8% respectively in metastatic colorectal adenocarcinoma. On the other hand, the expression rates of CK7, CK19 and CK20 in intrahepatic cholangiocarcinoma were 73.0%, 53.0% and 15.0% respectively, in contrast to 14.3%, 90.5% and 85.7% respectively in metastatic colorectal adenocarcinoma. The difference in expressions of MUC2, MUC6, CK7 and CK20 carried statistical significance.

CONCLUSIONSThe immunoprofile for mucin glycoproteins and cytokeratins provides important clues in distinguishing between intrahepatic cholangiocarcinoma and metastatic colorectal adenocarcinoma to liver. The immunophenotype of MUC2-/MUC6-/CK7+/CK20- indicates the diagnosis of intrahepatic cholangiocarcinoma, while MUC2+/MUC6+/CK7-/CK20+ suggests the possibility of metastatic colorectal adenocarcinoma.

Adenocarcinoma ; metabolism ; pathology ; Aged ; Bile Duct Neoplasms ; genetics ; metabolism ; pathology ; Bile Ducts, Intrahepatic ; pathology ; Biomarkers, Tumor ; analysis ; Cholangiocarcinoma ; genetics ; metabolism ; pathology ; Colorectal Neoplasms ; metabolism ; pathology ; Female ; Glycoproteins ; metabolism ; Humans ; Keratins ; metabolism ; Male ; Middle Aged ; Mucins ; metabolism ; Neoplasm Staging ; classification