THE IMMUNOHISTOCHEMICAL DISCRIMINATION OF ENDOMETRIOID ADENOCARCINOMAS

Carcinomas of endometrioid histology frequently arise in the endometri um, ovary, and endocervix and involve the pelvic tissues in women. Ade nocarcinomas of psuedoendometrioid morphology developing in the colon also frequently involve the ovary. The authors retrospectively examine d 97 adenocarcinomas from the uterus, cervix, ovary, and colon to asce rtain whether the site of origin could be determined by using a batter y of antibodies with the immunoperoxidase method on formalin-fixed tis sue. This study was restricted to tumors with endometrioid morphology. There were 27 endometrial, 16 ovarian, 23 endocervical adenocarcinoma s, and 31 pseduoendometrioid colonic adenocarcinomas. The battery of a ntibodies included vimentin (V), monoclonal carcinoembryonic antigen ( mCEA), and monoclonal CEA D-14. V-positive cells were defined by the p resence of a crisp paranuclear band of staining, and CEA-positive cell s showed irregular or diffuse cytoplasmic staining. V diffusely decora ted 22 of 27 (81.4%) of endometrial tumors, 3 of 23 (13%) of endocervi cal tumors (rare, focal staining), diffusely stained 5 of 16 (31.3%) o f ovarian tumors, and was rare and focal in 2 of 31 (6.4%) of colon tu mors. Both CEA antibodies were negative for cytoplasmic staining in bo th endometrial and ovarian tumors, but decorated from 65.2% (CEA D-14) to 95.6% (monoclonal CEA) of endocervical tumors and from 83.8% (CEA D14) to 90.3% (mCEA) of colonic tumors. The authors conclude that endo metrioid adenocarcinomas developing in endometrium and ovary are most often strongly V positive and CEA negative, which greatly aids in dist inguishing them from endometrioid or pseudoendometrioid tumors arising in endocervix and colon, which are only rarely, and very focally V an d CEA positive. These antibodies do not allow for discrimination betwe en endocervical and colonic tumors. CEA D-14 offered no immunodiagnost ic superiority over mCEA. These results support the use of immunohisto chemistry in assisting in the distinction of endometrial from endocerv ical primary sites in curettage specimens and in metastatic sites. Cop yright (C) 1996 by W.B. Saunders Company.