Objective: To 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.
Methods: One 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.
Results: In 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.
Conclusions: The 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.