Common epithelial ovarian tumors. Immunohistochemical intermediate filament profiles

The authors studied 79 common epithelial ovarian tumors in order to ascertain the intermediate filament profiles in formalin-fixed and methacarn-fixed, paraffin-embedded surgical pathology materials. Ultra-structural correlations were attempted with several tumors. All categories of common benign and malignant epithelial tumors were examined. Antibodies used in the study included antikeratins (AE1/AE3, 35BH11, 34BE12), carcinoembryonic antigen (CEA), and vimentin. All ovarian epithelial tumors expressed keratin in uniform fashion, except high molecular weight keratin (34BE12) which was focal. Vimentin was coexpressed with cytokeratins in 42% of serous carcinomas, 71% of endometrioid carcinomas, and 7% of clear cell carcinomas. Vimentin decoration in serous carcinoma was very focal, whereas endometrioid decoration tended to involve larger areas, similar to uterine-based endometrial adenocarcinoma. Mucinous, Brenner, and solid (not otherwise specified) ovarian tumors were positive only for cytokeratin. Carcinoembryonic antigen luminal staining was present in 52% of serous carcinomas and 87% of mucinous carcinomas. Whereas there are distinct differences in intermediate filament expression among ovarian carcinomas, these differences do not allow for specific categorization of ovarian neoplasms because there is some overlap of intermediate filament expression. In order to differentiate ovarian carcinoma from other carcinomas and mesothelioma, other methods of study would be necessary in addition to intermediate filament profiles, such as CEA immunohistochemistry, mucin histochemistry, and ultrastructural study.