Leptomeningeal dissemination of malignant glioma: immunohistochemical analysis of tenascin and glial fibrillary acidic protein.

Immunohistochemical expression of tenascin (TN) and glial fibrillary acidic protein (GFAP) was investigated in 9 human malignant gliomas with leptomeningeal dissemination. In these patients intracerebral glioma tissues obtained at operation and/or autopsy displayed localized expression of TN in tumor vessels and stroma. In contrast, TN was expressed in the tumor vessels, tumor stroma, and the cytoplasm of tumor cells to a high degree throughout all the leptomeningeal tumor tissues obtained at autopsy, whereas there was much less expression of GFAP in these tissues than at the primary site. These findings suggest that TN expression and decrease of GFAP expression in glioma tissue may be involved in the development of leptomeningeal dissemination.