CNS tumor
Tumors
World Health Organization (WHO) classification

Author: Maria Martinez-Lage, M.D. (see Authors page)

Revised: 8 November 2016, last major update November 2016

Copyright: (c) 2005-2016, PathologyOutlines.com, Inc.

PubMed Search: WHO classification [title] CNS tumors

Cite this page: WHO classification. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/cnstumorwhoclassification.html. Accessed December 9th, 2016.
Definition / General
Essential Features
WHO Revised 4th Edition (2016)—Summary
  • The 2016 update incorporates many significant changes (Acta Neuropathol 2016;131:803), most importantly the definition of new entities based on molecular characteristics for the first time, and the endorsement of the use of "integrated" diagnosis that incorporate phenotypic and genotypic information in a layered format (Brain Pathol 2014;24:429)
  • Gliomas are entirely restructured; astrocytomas and oligodendrogliomas are now under the same category ("diffuse astrocytic and oligodendroglial tumors"), which are further defined by the presence or absence of IDH mutations fundamentally
  • Medulloblastomas are restructured with incorporation of molecularly defined entities that determine prognostic categories
  • NOS (not otherwise specified): terminology to be used when molecular information is insufficient, either because testing cannot be fully performed or the results don’t fit within a defined category
  • New entities have been added, such as diffuse midline glioma, H3 K27M mutant, diffuse leptomeningeal glioneuronal tumor and epithelioid glioblastoma
  • Some entities, variants and patterns have been deleted, such as gliomatosis cerebri (now considered a pattern instead of an entity) and "Primitive neuroectodermal tumor" (PNET) terminology for embryonal tumors
  • Brain invasion is added as a criterion for atypical meningioma, WHO grade II
  • Solitary fibrous tumor and hemangiopericytoma are now considered a combined diagnosis (solitary fibrous tumor / hemangiopericytoma)
    • They are graded 1 - 3 using a soft tissue type grading system
    • This represents the first time that grading of CNS tumors is applied within a single entity - typically each entity is assigned a single WHO grade
  • Nerve sheath tumors are expanded, with incorporation of hybrid nerve sheath tumor and separation of melanotic schwannoma from others
  • Terminology
    • Diffuse astrocytic and oligodendroglial tumors:
      • Diffuse astrocytoma, IDH mutant
      • Gemistocytic astrocytoma, IDH mutant
      • Diffuse astrocytoma, IDH wild type
      • Diffuse astrocytoma, NOS
      • Anaplastic astrocytoma, IDH mutant
      • Anaplastic astrocytoma, IDH wild type
      • Anaplastic astrocytoma, NOS
      • Glioblastoma, IDH wild type
      • Giant cell glioblastoma
      • Gliosarcoma
      • Epithelioid glioblastoma
      • Glioblastoma IDH mutant
      • Glioblastoma, NOS
      • Diffuse midline glioma H3 K27M mutant
      • Oligodendroglioma, IDH mutant and 1p / 19q codeleted
      • Oligodendroglioma, NOS
      • Anaplastic oligodendroglioma, IDH mutant and 1p / 19q codeleted
      • Anaplastic oligodendroglioma, NOS
      • Oligoastrocytoma, NOS
      • Anaplastic oligoastrocytoma, NOS

    • Other astrocytic tumors:
      • Pilocytic astrocytoma
      • Pilomyxoid astrocytoma
      • Subependymal giant cell astrocytoma
      • Pleomorphic xanthoastrocytoma, anaplastic pleomorphic xanthoastrocytoma

    • Ependymal tumors:
      • Subependymoma
      • Myxopapillary ependymoma
      • Ependymoma
      • Papillary ependymoma
      • Clear cell ependymoma
      • Tanycytic ependymoma
      • Ependymoma, RELA fusion positive
      • Anaplastic ependymoma

    • Other gliomas:
      • Chordoid glioma of the third ventricle
      • Angiocentric glioma, astroblastoma

    • Choroid plexus tumors:
      • Choroid plexus papilloma
      • Atypical choroid plexus papilloma
      • Choroid plexus carcinoma

    • Neuronal and mixed neuronal-glial tumors:
      • Dysembryoplastic neuroepithelial tumor
      • Gangliocytoma ganglioglioma
      • Anaplastic ganglioglioma
      • Dysplastic cerebellar gangliocytoma (Lhermitte-Duclos disease)
      • Desmoplastic infantile astrocytoma and ganglioglioma
      • Papillary glioneuronal tumor
      • Rosette forming glioneuronal tumor
      • Diffuse leptomeningeal glioneuronal tumor
      • Central neurocytoma
      • Extraventricular neurocytoma
      • Cerebellar liponeurocytoma
      • Paraganglioma

    • Tumors of the pineal region:
      • Pineocytoma
      • Pineal parenchymal tumor of intermediate differentiation
      • Pineoblastoma
      • Papillary tumor of the pineal region

    • Embryonal tumors:
      • Medulloblastoma, WNT activated
      • Medulloblastoma, SHH activated and TP53 mutant
      • Medulloblastoma, SHH activated and TP53 wildtype
      • Medulloblastoma, non WNT / non SHH
      • Medulloblastoma, group 3
      • Medulloblastoma, group 4
      • Medulloblastoma, classic
      • Medulloblastoma, desmoplastic / nodular
      • Medulloblastoma with extensive nodularity
      • Medulloblastoma, large cell / anaplastic
      • Medulloblastoma, NOS
      • Embryonal tumor with multilayered rosettes, C19MC altered
      • Embryonal tumor with multilayered rosettes, NOS
      • Medulloepithelioma
      • CNS neuroblastoma
      • CNS ganglioneuroblastoma
      • CNS embryonal tumor, NOS
      • Atypical teratoid rhabdoid tumor
      • CNS embryonal tumor with rhabdoid features

    • Tumors of the cranial and paraspinal nerves:
      • Schwannoma
      • Cellular schwannoma
      • Plexiform schwannoma
      • Melanotic schwannoma
      • Neurofibroma
      • Atypical neurofibroma
      • Plexiform neurofibroma
      • Perineurioma
      • Hybrid nerve sheath tumor
      • Malignant peripheral nerve sheath tumor (MPNST)
      • Epithelioid MPNST
      • MPNST with perineurial differentiation

    • Meningiomas:
      • Meningioma
      • Meningothelial meningioma
      • Fibrous meningioma
      • Transitional meningioma
      • Psammomatous meningioma
      • Angiomatous meningioma
      • Microcystic meningioma
      • Secretory meningioma
      • Lymphoplasmacyte rich meningioma
      • Metaplastic meningioma
      • Chordoid meningioma
      • Clear cell meningioma
      • Atypical meningioma
      • Papillary meningioma
      • Rhabdoid meningioma
      • Anaplastic (malignant) meningioma

    • Mesenchymal, nonmeningothelial tumors:
      • Solitary fibrous tumor / hemangiopericytoma
      • Hemangioblastoma
      • Hemangioma
      • Epithelioid hemangioendothelioma
      • Angiosarcoma
      • Kaposi sarcoma
      • Ewing sarcoma / PNET
      • Lipoma angiolipoma
      • Hibernoma
      • Liposarcoma
      • Desmoid type fibromatosis
      • Myofibroblastoma
      • Inflammatory myofibroblastic tumor
      • Benign fibrous histiocytoma
      • Fibrosarcoma
      • Undifferentiated pleomorphic sarcoma / malignant fibrous histiocytoma
      • Leiomyoma
      • Leiomyosarcoma
      • Rhabdomyoma
      • Rhabdomyosarcoma
      • Chondroma
      • Chondrosarcoma
      • Osteoma
      • Osteochondroma
      • Osteosarcoma

    • Melanocytic tumors:
      • Meningeal melanocytosis
      • Meningeal melanocytoma
      • Meningeal melanoma
      • Meningeal melanomatosis

    • Lymphomas:
      • Diffuse large B-cell lymphoma (DLBCL) of the CNS
      • Immunodeficiency associated
      • AIDS related DLBCL
      • EBV positive DLBCL
      • Lymphomatoid granulomatosis
      • Intravascular large B-cell lymphoma
      • Low grade B-cell lymphomas of the CNS
      • T-cell and NK / T-cell lymphomas of the CNS
      • Anaplastic large cell lymphoma, ALK positive
      • Anaplastic large cell lymphoma, ALK negative
      • MALT lymphoma of the dura

    • Histiocytic tumors:
      • Langerhans cell histiocytosis
      • Erdheim-Chester disease
      • Rosai-Dorfman disease
      • Juvenile xanthogranuloma
      • Histiocytic sarcoma

    • Germ cell tumors:
      • Germinoma
      • Embryonal carcinoma
      • Yolk sac tumor
      • Choriocarcinoma
      • Teratoma
      • Mature teratoma
      • Immature teratoma
      • Teratoma with malignant transformation
      • Mixed germ cell tumor

    • Tumors of the sellar region:
      • Craniopharyngioma
      • Adamantinomatous craniopharyngioma
      • Papillary craniopharyngioma
      • Granular cell tumor of the sellar region
      • Pituicytoma
      • Spindle cell oncocytoma

    • Metastatic tumors
    Classification

    The 2016 WHO classification of CNS tumors

    Grading
    • Histological grading is still used based on morphology, despite the very important prognostic significance of the molecular characteristics (i.e. IDH mutant vs IDH wild type gliomas)
    • In the clinical setting, tumor grade remains a key factor influencing choice of therapy

    2016 WHO Grades of Select Tumors
    of the Central Nervous System