The choice of appropriate therapeutic plans for primary endocervical
adenocarcinomas and endometrial
adenocarcinomas depends on the site of origin of the
tumor. The purpose of this study was to make clear whether the immunohistochemistry of the true
cytokeratin 8/18
monoclonal antibody (Leica Microsystems, Newcastle, United Kingdom), instead of CAM 5.2 (Becton Dickinson Biosciences, San Jose, CA), has potential use in distinguishing between endocervical
adenocarcinomas and endometrial
adenocarcinomas. A tissue microarray was constructed using
paraffin-embedded,
formalin-fixed tissues from 34
hysterectomy specimens, including 14 endocervical
adenocarcinomas and 20 endometrial
adenocarcinomas. Using the Bond-Max autostainer (Leica Microsystems) and the associated Bond Refine
Polymer Detection Kit, tissue array sections were immunostained with
cytokeratin 8, 18, and 8/18 commercially available
antibodies. The immunohistochemical expressions of all 3 markers,
cytokeratin 8, 18, and 8/18 showed nonsignificant (P>0.05) frequency differences between the immunostaining results (positive vs. negative) in
tumors of both gynecologic
adenocarcinomas. Although CAM 5.2 has been reported to be helpful in distinguishing between primary endocervical
adenocarcinomas and endometrial
adenocarcinomas, we could not verify this point of view using the true
cytokeratin 8/18
monoclonal antibody (Leica Microsystems). It has often been mistakenly cited that CAM 5.2 reacts with
cytokeratin 8 and 18, and the results herein confer that there is a wrong impression that
cytokeratin 8/18 is differentially expressed in these 2 gynecologic
malignancies. In conclusion, the true
cytokeratin 8/18
monoclonal antibody is of no use in distinguishing between primary endocervical
adenocarcinomas and endometrial
adenocarcinomas.