WHO Classification of CNS & PNS Tumors
Grading System
G1
- Low proliferative potential
- Typically, well circumscribed and amenable to surgical resection
G2
- Atypical cells with infiltrative potential
- Cells have low mitotic activity
G3
- Nuclear atypia, significant infiltrative capacity
- Cells have increased mitotic activity
G4
- Demonstrate nuclear atypia and their cells are mitotically active
- They develop necrosis and neovascularity
- They infiltrate and disseminate (metastasize)
Diffuse astrocytic and oligodendroglial tumors
- Diffuse astrocytoma (IDH-mutant), G2
- Anaplastic astrocytoma (IDH-mutant), G3
- Glioblastoma (IDH-wildtype), G4
- Glioblastoma (IDH-mutant), G4
- Diffuse midline glioma (H3 K27M-mutant), G4
- Oligodendroglioma (IDH-mutant & 1p/19q-codeleted), G2
- Anaplastic oligodendroglioma (IDH-mutant & 1p/1q-codeleted), G3
Other astrocytic tumors
- Pilocytic astrocytoma, G1
- Subependymal giant cell astrocytoma, G1
- Pleomorphic xanthoastrocytoma, G2
- Anaplastic pleomorphic xanthoastrocytoma, G3
Ependymal tumors
- Subependymoma, G1
Myxopapillary ependymoma
- Myxopapillary ependymoma, G1
- Ependymoma, G2
- Ependymoma, (RELA fusion-positive), G2 or G3
- Anaplastic ependymoma, G3
Other gliomas
- Angiocentric glioma, G1
- Choroid glioma of the 3rd ventricle, G2
Choroid plexus tumors
Choroid plexus papilloma/carcinoma
- Choroid plexus papilloma, G1
- Atypical choroid plexus papilloma, G2
- Choroid plexus carcinoma, G3
Neuronal & mixed neuronal-glial tumors
- Dysembryoblastic neuroepithelial tumor (DNET), G1
- Gangliocytoma, G1
- Ganglioglioma, G1
- Anaplastic ganglioglioma, G3
- Dysplastic ganglioglioma of cerebellum (Lhermitte-Duclos), G1
- Desmoplastic infantile astrocytoma and ganglioglioma, G1
- Papillary glioneuronal tumor, G1
- Rosette-forming glioneuronal tumor, G1
- Central neurocytoma, G2
- Extraventricular neurocytoma, G2
- Cerebellar liponeurocytoma, G2
- Pineocytoma, G1
- Pineal parenchymal tumor of intermediate differentiation, G2 or G3
- Pineoblastoma, G4
- Papillary tumor of the pineal region, G2 or G3
- Medulloblastoma, G4
- Embryonal tumor with multilayered rosettes (C19MC-altered), G4
- Medulloepithelioma, G4
- CNS embryonal tumor, NOS, G4
- Atypical teratoid/rhabdoid tumor, G4
- CNS embryonal tumor with rhabdoid features, G4
- See also: neuroblastoma
Tumors of the cranial and paraspinal nerves
- Schwannoma, G1
- Neurofibroma, G1
- Perineurioma, G1
- Malignant peripheral nerve sheath tumor, G2, 3, or 4
- Meningioma, G1
- Atypical meningioma, G2
- Anaplastic (malignant) meningioma, G3
Mesenchymal, non-meningothelial tumors
- Solitary fibrous tumor/hemangiopericytoma, G1, G2, or G3
- Hemangioblastoma, G1
Tumors of the sellar region
- Craniopharyngioma, G1
- Granular cell tumor, G1
- Pituicytoma, G1
- Spindle cell oncocytoma, G1
- Designated an Endocrine Organ Tumor, but commonly affects the CNS, so included here.
Additional, Related Tumors/Mass Lesions
References
- Louis, David N., Arie Perry, Guido Reifenberger, Andreas von Deimling, Dominique Figarella-Branger, Webster K. Cavenee, Hiroko Ohgaki, Otmar D. Wiestler, Paul Kleihues, and David W. Ellison. “The 2016 World Health Organization Classification of Tumors of the Central Nervous System: A Summary.” Acta Neuropathologica 131, no. 6 (June 1, 2016): 803–20. https://doi.org/10.1007/s00401-016-1545-1.
Figure Adapted From:
- Louis, David N., Arie Perry, Guido Reifenberger, Andreas von Deimling, Dominique Figarella-Branger, Webster K. Cavenee, Hiroko Ohgaki, Otmar D. Wiestler, Paul Kleihues, and David W. Ellison. “The 2016 World Health Organization Classification of Tumors of the Central Nervous System: A Summary.” Acta Neuropathologica 131, no. 6 (June 1, 2016): 803–20. https://doi.org/10.1007/s00401-016-1545-1.