Application of antibodies to intermediate filament proteins in simple and complex tumors of the female genital tract.

Polyclonal antibodies to cytokeratins, vimentin, and desmin and monoclonal antibodies to vimentin and to individual cytokeratin polypeptides, specific for glandular epithelia (RGE 53) or kertinizing stratified squamous epithelia (RKSE 60), have been applied in gynecological tumors with simple or complex composition. In general, tumors with simple composition showed reaction patterns fitting their known epithelial or mesenchymal nature, i.e., cytokeratin positivity in epithelial tumors only, vimentin positivity in mesenchymal tumors, and expression of desmin and vimentin in muscle cell tumors. Rather frequently, coexpression of cytokeratins and vimentin was noted in endometrial adenocarcinomas. Tumors with complex composition, such as müllerian mesodermal mixed tumors (MMMTs), that may pose considerable problems in conventional histopathology revealed various reaction patterns, with either expression of only cytokeratins or coexpression of cytokeratins and vimentin in carcinomatous areas and expression of only vimentin in sarcomatous areas. However, in addition, some MMMTs contained cells that were also positive for desmin. Intermediate filament protein immunohistochemistry appeared to be helpful in establishing a diagnosis of MMMT and in characterizing the different tumor components, which may prove to be useful in the evaluation of gynecological treatment protocols.