CYTOKERATIN-7 AND CYTOKERATIN-20 AND CARCINOEMBRYONIC ANTIGEN IN OVARIAN AND COLONIC-CARCINOMA

The histologic distinction between adenocarcinoma primary to the ovary and metastatic to the ovary can be difficult. In an effort to facilit ate this distinction, we have evaluated the use of immunohistochemical techniques with antibodies to cytokeratins 7 and 20, along with antib odies to carcinoembryonic antigen. We studied 24 primary ovarian adeno carcinomas, 11 colonic adenocarcinomas metastatic to the ovary, and 10 primary adenocarcinomas of the colon. Four ovarian adenocarcinomas me tastatic to the colon were also studied. All but one of the primary an d metastatic colonic carcinomas were negative for cytokeratin 7, where as all the primary and metastatic ovarian carcinomas were positive for cytokeratin 7. The tumors metastatic to the ovary were all positive f or cytokeratin 20 and carcinoembryonic antigen. Among the primary ovar ian carcinomas, none of six serous tumors, three of seven endometrioid tumors, and three of 11 mucinous tumors were positive for cytokeratin 20. Ten of the primary ovarian tumors were negative for carcinoembryo nic antigen using both monoclonal and polyclonal antibodies. One of th e ovarian tumors was negative for carcinoembryonic antigen with the mo noclonal antibody but positive using the polyclonal antibody. Cytokera tin 7 is the most helpful marker in the distinction between primary ov arian carcinoma and colonic carcinoma metastatic to the ovary.