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used system for grading diffuse astrocytomas (at the time of writing i.e. mid-2016) and is an adaptation of the now superseded St Anne-Mayo grading system (also known as the Daumas-Duport grading system).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