Nomenclature for gliomas.

Gliomas, derived from astrocytes, oligodendroglia, or ependyma, are each united into a continuum by a graduation of anaplasia. Neoplasms originate at all levels of each continuum; subsequently, some move along its declivity. Conversely, neuroblastic tumors may differentiate, whereas concomitantly in the same lesion, the glial stroma may dedifferentiate. Anaplastic glia, as in a glioblastoma multiforme, can initiate malignant transformation in alien cells.