• Gliomas
• 50.3%
• Meningiomas
• 20.9%
• Pituitary adenomas
  
• 15%
• Nerve sheath tumors
  
• 8%

Grading

• Low-grade
  
• WHO grade II
• Well-differentiated (not anaplastic)
• High-grade
• WHO grade III-IV
• Undifferentiated (anaplastic)

Gliomas

• Ependymomas
• Ependyma is the thin epithelial membrane lining the ventricular system of the brain and the spinal cord
• Common location of intracranial ependymoma is the fourth ventricle
• Astrocytomas 
• Slow growing astrocytoma (grade I)
• Slow growing astrocytoma (grade II)
• Anaplastic astrocytoma (grade III)
• Glioblastoma multiforme (grade IV)
• May form by progression from lower grades (10%)
  
• Oligodendrogliomas
  
• Mixed gliomas
• Such as oligoastrocytomas

Glial cell types

• Astrocytes
• Chemistry
  
• Oligodendrocytes
• Myelin
  
• Ependymal cells
• CSF
  
• Radial glia
• Progenitors/Scaffold