The WHO grading system is the most widely used system for grading diffuse astrocytomas (at the time of writing i.e. mid 2016), and is an adaptation of the now superseded St Anne-Mayo grading system (also known as the Daumas-Duport grading system).
Grade I is reserved for localised astrocytomas (see WHO classification of CNS tumours for a complete list) and as such diffuse astrocytomas range in grade from grade II to IV.
Grade II: low grade infiltrative astrocytoma
- cellular atypia only
Grade III: anaplastic astrocytoma
- increased mitotic activity
- cellular anaplasia
Grade IV: glioblastoma
- vascular proliferation
- necrosis typically with perinecrotic palisading
Gliomatosis cerebri does not have its own grade, but rather is a highly infiltrative version of a low grade or anaplastic tumour which involves at least three lobes 5. It does however confer a worse prognosis.
It is worth noting that there are other grading systems (see diffuse astrocytoma grading) and the pros and cons of each have been the subject of extensive debate.
- 1. Jörg-Christian Tonn, Manfred Westphal, James T. Rutka. Oncology of CNS Tumors. Springer. (2010) ISBN:3642028748. Read it at Google Books - Find it at Amazon
- 2. Kleihues P, Burger PC, Scheithauer BW. The new WHO classification of brain tumours. Brain Pathol. 1993;3 (3): 255-68. - Pubmed citation
- 3. Louis DN, Ohgaki H, Wiestler OD et-al. The 2007 WHO classification of tumours of the central nervous system. Acta Neuropathol. 2007;114 (2): 97-109. Acta Neuropathol. (full text) - doi:10.1007/s00401-007-0243-4 - Free text at pubmed - Pubmed citation
- WHO classification of CNS tumours
- WHO grading of CNS tumours
- VASARI MRI feature set
- diffuse astrocytoma grading
- grade I:
- grade II:
- grade III
- grade IV:
- glioblastoma vs cerebral metastasis
- radiation-induced gliomas
- gliomatosis cerebri (growth pattern)
- specific locations
- treatment response
- Stupp protocol
- glioma treatment response assessment in clinical trials
- multicentric glioblastoma
- multifocal glioblastoma
- prognostic genetic markers