Table 1:

WHO grading of Glioma

Grade	Characteristics	Tumor Types
I	Low proliferative potential	Pilocytic Astrocytoma
II	Low proliferative potential, but infiltrative. Often recur and can progress to higher grade tumors	Astrocytoma Oligodendroglioma Oligoastrocytoma
III	Demonstrate histological evidence of malignancy: 1. Hypercellularity 2. Nuclear atypia 3. Increased mitotic activity	Anaplastic Astrocytoma Anaplastic Oligodendroglioma Anaplastic Oligoastrocytoma
IV	Demonstrate histological evidence of malignancy: 1. Hypercellularity 2. Nuclear atypia 3. Increased mitotic activity Plus vascular proliferation and presence of necrosis	Glioblastoma