On the Genesis of Neuroblastoma and Glioma

Table 2

WHO classification of glial tumours of the CNS.

1	Subependymal giant cell astrocytoma; Subependymoma; Myxopapillary ependymoma; Pilocytic astrocytoma; Gangliocytoma; Ganglioglioma; Paraganglioma of the spinal cord; Rosette-forming glioneuronal tumour of the fourth ventricle	Low proliferative potential and the possibility of cure by surgical resection
2	Ependymoma; Pilomyxoid astrocytoma; Diffuse astrocytoma; Pleomorphic xanthoastrocytoma; Oligodendroglioma; Choroid glioma of the third ventricle	Diffusely infiltrative glial tumours with cytological atypia, often recurrent
3	Anaplastic astrocytoma; Anaplastic oligodendroglioma; Anaplastic oligoastrocytoma; Anaplastic ependymoma; Anaplastic ganglioglioma	As grade 2 plus anaplasia (i.e., dedifferentiation, pleomorphism, and hyperploidy) and mitotic activity
4	Glioblastoma; Gliosarcoma; Giant cell glioblastoma	As grade 3 plus microvascular proliferation and/or necrosis, virtually incurable