Meningiomas and arachnoid cells: an immunohistochemical study of epithelial markers.

Twenty-nine cases of meningioma were studied by immunoperoxidase staining using broad-spectrum antibodies to cytokeratin (AE1/AE3), carcinoembryonic antigen (CEA) and epithelial membrane antigen (EMA). Twenty-six cases (90%) showed positive staining for EMA. All cases were negative for cytokeratin and CEA except for the two cases of secretory meningioma. Normal arachnoidal cells of the leptomeninges from 15 autopsies were studied similarly, and 10 cases (67%) demonstrated positive staining for EMA, but not for CEA and cytokeratin. Literature from previous investigations on epithelial markers of meningiomas is reviewed. It is concluded that meningiomas and normal arachnoidal cells share similar immunohistochemical properties, and that EMA is a useful epithelial marker for meningiomas.