Reactive astrocytes in the morphologic composition of peripheral areas of gliomas.

The participation of reactive astrocytes in the morphologic composition of peripheral areas of 25 gliomas was investigated. Reactive astrocytes were studied by the immunohistochemical demonstration of glial fibrillary acidic protein and vimentin. Reactive astrocytes were more abundant around malignant gliomas than around well-differentiated astrocytomas. They underwent modifications when entrapped within the tumor proliferation and became indistinguishable from tumor astrocytes. Mitoses occurred in both types of cells. Reactive astrocytes did participate in the cell composition of gliomas. They might have contributed to tumor growth. Practically, their occurrence might lead to an erroneous diagnosis when small fragments of tissue are examined.