Table 1. WHO 2007 classification for diffuse gliomas.
| Type | Grade | Description | Median survival (years) |
|---|---|---|---|
| Astrocytoma | II | Found diffusely infiltrating into surrounding neural tissue; increased hypercellularity, no mitosis | 6-8 |
| Oligodendroglioma | II | Occur in the white matter and cortex of the cerebral hemispheres, low mitotic activity, no necrosis | 12 |
| Oligoastrocytoma | II | Diffuse mixed tumor with mixed glial background | 3 to >10 |
| Anaplastic-astrocytoma/oligodendroglioma | III | Highly infiltrating tumors with increased mitotic activity; no necrosis or vascular proliferation | 3 |
| Glioblastoma | IV | Infiltrating glial neoplasm with necrosis and micro-vascular proliferation; high rate of mitosis |
1 to 2 |
WHO, World Health Organization.