Classification of Astrocytomas
| Kernohan (1940) | Mayo/St. Anne (1981/1988) | WHO grade (1979/1993) | WHO designation | Histopathology |
|---|---|---|---|---|
| Grade 1 | Excluded | I | Pilocytic astrocytoma | Bipolar, piloid cells, Rosenthal fibers, eosinophilic granular bodies |
| Grade 1 | Grades 1 and 2 | II | Low-grade astrocytoma | Neoplastic fibrillary or gemistocytic astrocytes; nuclear atypia |
| Grade 2 | Grade 3 | III | Anaplastic astrocytoma | Neoplastic fibrillary or gemistocytic astrocytes; nuclear atypia mitotic activity |
| Grade 3 Grade 4 | Grade 4 | IV | Glioblastoma multiforme | Cellular anaplasia, nuclear atypia, mitoses, vascular proliferation, necrosis |
Table modified from Kleihues (3) and Tatter (6).