Coexpression of cytokeratins and vimentin in common epithelial tumours of the ovary: an immunocytochemical study of eighty-three cases.

An immunocytochemical investigation has been performed on 83 common epithelial tumours of the ovary, to ascertain their capability of expressing vimentin in addition to cytokeratins. Our results demonstrate that vimentin coexpression is related to the tumour histotype and -to a lesser extent- to the degree of differentiation of malignant variants. Indeed, most serous tumours (80%), some endometrioid adenocarcinomas, and all the clear cell carcinomas investigated exhibited a variable number of neoplastic cells co-synthesizing the two distinct intermediate filament (IF) proteins, whereas only one of 29 mucinous tumours and none of the Brenner tumours displayed vimentin-immunoreactive cells. Moreover, in serous and endometrioid carcinomas, the expression of vimentin was related to the degree of tumour differentiation, being consistently identifiable in the better differentiated cases. The immunocytochemical findings of a parallel investigation on IF expression in the ovarian coelomic epithelium and in the müllerian-derived epithelia of the female genital tract allowed us to ascertain that ovarian epithelial tumours (with the possible exception of poorly differentiated carcinomas) maintain the pattern of IF expression typical of the normal epithelia. This investigation emphasizes the usefulness of IF typing as a tool for the more precise characterization of the origin and differentiation of human neoplasms.