Primary cervical adenocarcinoma with intestinal differentiation and colonic carcinoma metastatic to cervix. An investigation using CDX-2 and a limited immunohistochemical panel.

Context.-Cdx-2 is expressed in normal colonic epithelia and in most colorectal adenocarcinomas. No data exist on Cdx-2 expression in primary cervical adenocarcinoma with colonic differentiation. Objective.-To ascertain the utility of Cdx-2 and a limited immunohistochemical panel in differentiating between primary cervical adenocarcinoma with intestinal differentiation and secondary (colonic) cervical adenocarcinoma, which call for different surgical and chemotherapeutic treatment protocols. Design.-We examined cervical tract adenocarcinomas in women with previously negative medical histories for neoplastic disease and in women with colonic carcinoma. An immunohistochemical panel consisting of cytokeratin 7, cytokeratin 20, carcinoembryonic antigen, and a new marker, Cdx-2, was evaluated in all cases. The clinical data, the morphologic features, and the immunohistochemical staining patterns were compared. Results.-Of the tumors diagnosed as metastatic intestinal adenocarcinoma of the cervix, based on clinical data and hematoxylin-eosin-stained sections, all were Cdx-2 positive, whereas Cdx-2 was not expressed in any of our cases of primary cervical adenocarcinoma with colonic differentiation. Carcinoembryonic antigen was expressed both in primary cervical tumor and in secondary (intestinal) cervical adenocarcinoma. Cytokeratin 20 was not expressed in our cases of cervical adenocarcinoma, and it was not expressed in 7.15% of cervical metastases from intestinal carcinoma. Immunostaining with cytokeratin 7 was positive in cervical adenocarcinoma, but was negative in secondary (intestinal) cervical adenocarcinoma. Conclusions. -Our immunohistochemical analysis shows that Cdx-2 has good specificity and would be a good marker to use in a limited panel of immunohistochemical markers, such as cytokeratin 7, cytokeratin 20, and carcinoembryonic antigen, to distinguish primary cervical adenocarcinoma from intestinal metastases to the cervix.