[Basic principles of electron microscopic diagnosis of human brain tumors].

Electron microscopy of two hundred brain tumours of various origin allowed the authors to elaborate the main principles of electron microscopic diagnosis. A comprehensive approach to determining the comparative diagnostic value of the morphological signs of the tumour and the initial normal tissue and the high resolving capacity of the electron microscope provide for trustworthy identification of tissue origin of the new growth that is examined. The electron microscopic method is particularly important when diagnostic difficulties arise on the light-optic level of the morphological examination.