Epithelial membrane antigen and cytokeratin expression by meningiomas: an immunohistological study.

Thirteen meningiomas of varying light microscopic features were studied immunohistologically using a panel of monoclonal antibodies directed against epithelial, mesenchymal, and neural components. All 13 meningiomas showed expression of epithelial membrane antigen, vimentin, and S100 protein, as did normal meninges. Five of the 13 meningiomas also showed focal expression of cytokeratins, with double labelling showing expression of cytokeratins and vimentin by different cells. The cytokeratin expression was especially noticeable in cells surrounding the hyaline bodies of meningiomas. These results provide further evidence that meningiomas have features of both mesenchymal and epithelial tissues.