OBJECTIVETo evaluate the significance of a panel of immunohistochemical markers for distinguishing hepatocellular carcinoma (HCC) from intrahepatic cholangiocarcinoma (ICC).

METHODSTen markers including hepatocyte paraffin 1 (Hep Par 1), polyclonal carcinoembryonic antigen (pCEA), CD34, CD10, CD105, multidrug resistance-associated protein-3 (MRP-3), cyclooxygenase-2 (COX-2), mucinous glycoprotein-1 (MUC-1), aquaporin-1 (AQP-1) and CK19 were immunohistochemically stained in the samples from 90 surgically resected HCC and 80 ICC, respectively,and the positive rate of their expression were compared statistically.

RESULTSThe positive expression rates of Hep Par 1, pCEA, CD34, CD10, CD105, MRP-3, COX-2 were 85.6%, 82.2%, 87.8%, 18.9%, 8.9%, 11.1% and 48.9%, respectively, in HCC. While the positive expression rates of MUC-1, AQP-1 and CK19 were 73.8%, 65% and 92.5%, respectively, in ICC.

CONCLUSIONBased on our results, Hep Par 1 and CD34 can be used as the first line markers, and pCEA and COX-2 as the second line makers, for differential diagnosis of hepatocellular carcinoma from intrahepatic cholangiocarcinoma. While MUC-1 and CK19 can be used as the first line markers and AQP-1 as the second one for the differential diagnosis of intrahepatic cholangiocarcinoma from hepatocellular carcinoma.