• Diffuse gliomas, separated from the common group of glial tumours, as diffuse astrocytic and oligodendroglial tumours
    • Restructured with incorporation of genetically defined entities
  • Medulloblastomas are restructured with incorporation of genetically defined entities
  • Other embryonal tumors are also restructured, with incorporation of genetically defined entities
  • The term “primitive neuroectodermal tumor” is removed
  • Ependymoma - genetically defined variant of RELA fusion positive incorporated.
  • Newly recognized entities, variants and patterns added:
    • IDH-wildtype and IDH-mutant glioblastoma (entities)
    • Diffuse midline glioma, H3 K27M–mutant (entity)
    • Embryonal tumour with multilayered rosettes, C19MC-altered (entity)
    • Ependymoma, RELA fusion–positive (entity)
    • Diffuse leptomeningeal glioneuronal tumor (entity)
    • Anaplastic PXA (entity)
    • Epithelioid glioblastoma (variant)
    • Glioblastoma with primitive neuronal component (pattern)
    • Multinodular and vacuolated pattern of ganglion cell tumor (pattern)
  • Entities, variants and terms deleted:
    • Gliomatosis cerebri
    • Protoplasmic and fibrillary astrocytoma variants
    • Cellular ependymoma variant
    • “Primitive neuroectodermal tumour” terminology
  • Addition of brain invasion as a criterion for the diagnosis of atypical meningioma
  • Restructuring of solitary fibrous tumor and hemangiopericytoma (SFT/HPC) as one entity with grades from I to III
  • Addition of hybrid nerve sheath tumors and separation of melanotic schwannoma from other schwannomas
  • Expansion of entities included in hematopoietic/lymphoid tumors of the CNS (lymphomas and histiocytic tumors)

Louis DN, et al. The 2016 World Health Organization Classification of Tumors of the Central
Nervous System: a summary. Acta Neuropathol, 2016;6: 803-820