[1] The first tumor classified as grade I is called pilocytic astrocytoma and it is most commonly observed in children rather than adults.
Least aggressive ependymal tumors include Subependymomas and Myxopapillary ependymoma which are classified as grade I.
The most severe are classified as grade III and are called anaplastic ependymomas and these usually occur at the base of the spine.
[6] Oligodendroglioma are very different histologically, from brain tissue due to their sharp borders and their distinctive "fried egg" characteristic.
[6] This article incorporates public domain material from Dictionary of Cancer Terms.