THE EXPRESSION OF CYTOKERATIN-7, CYTOKERATIN-19, AND CYTOKERATIN-20 IN PRIMARY AND METASTATIC CARCINOMAS OF THE LIVER

We performed immunohistochemical studies on 90 surgically resected liv er tumors, including 30 tumors each from hepatocellular carcinoma (HCC ), cholangiocarcinoma (CC), and metastatic colorectal adenocarcinoma ( MCA), using monoclonal antibodies against cytokeratin (CK) 7, CK 19, a nd CK 20 to examine the differences in the CK expressions in primary a nd metastatic carcinomas of the liver, We also investigated the useful ness of such expression in the differential diagnosis in addition to e xisting markers such as alpha-fetoprotein, carcinoembryonic antigen, a nd carbohydrate antigen 19-9, For CK 7, all except for one (97%) of th e CCs were diffusely positive, whereas only two (7%) HCCs and one (3%) MCAs were diffusely positive. For CK 19, 23 (77%) CCs and 19 (64%) MC As were diffusely positive, whereas no HCCs were positive, For CK 20, 22 (74%) MCAs were diffusely positive, whereas no HCC and three (10%) CCs were diffusely positive, The findings concerning the expression of immunohistochemical CK are therefore considered to be useful in addit ion to the diagnostic criteria when making a differential diagnosis of primary and metastatic carcinomas of the liver.