The distribution of mucins, carcinoembryonic antigen, and mucus-associated antigens in endocervical and endometrial adenocarcinomas

The presence and distribution of mucins, carcinoembryonic antigen (CEA), and mucus-associated antigens M1, M2, and M3 were investigated in 22 normal endocervices, 25 normal endometria, 25 endocervical adenocarcinomas, and 32 endometrial adenocarcinomas to determine their contribution in the differential diagnosis of endocervical and endometrial adenocarcinoma. Sections of formalin-fixed paraffin-embedded tissues were stained with conventional histochemical stains such as d-PAS and Alcian blue to investigate the distribution of mucins. For the demonstration of CEA and the mucus-associated antigens an indirect immunoperoxidase technique was used. In the present study d-PAS and Alcian blue stains, as well as immunohistochemistry of CEA, did not contribute to the discrimination between adenocarcinomas of the endocervix and endometrium. Immunohistochemistry of mucus-associated antigens showed a positive reaction of M3 in the majority (68%) of the endocervical carcinomas. In contrast, if foci of endocervical-type metaplasia were excluded, M3 was absent in tumor cell cytoplasm of endometrial adenocarcinomas. Furthermore, the expression of M2 without the presence of the other mucus antigens in tumor cell cytoplasm, as seen in 24% of the endometrial adenocarcinomas, was never found in endocervical adenocarcinomas.