Abstract
The ultrastructural characteristics of glial and nonglial tumors are described. The glial tumors in this study are astrocytomas, malignant astrocytomas, oligodendrogliomas and ependymomas. The nongliomatous tumors are meningiomas, neurofibromas and neurilem-momas. The diagnostic utility of the electron microscope in identifying tumor types and submicroscopic abnormalities is clearly demonstrated.