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Table 1 cIMPACT-NOW updates

From: WHO classification of tumors of the nervous system: preview of the upcoming 5th edition

Update / year Main topics Highlights Comments
1/2018 Nomenclature, NOS vs. NEC NOS (“not otherwise specified”) and NEC (“not elsewhere classified”) NOS: molecular testing not available
NEC: test results do not fit known tumor
2/2018 H3K27m WHO grade 4 restricted to H3K27m diffuse midline gliomas Other tumors harboring the H3K27mut, not necessarily aggressive
Diffuse astrocytoma, IDHmut IDHmut, ATRX loss, diffuse p53-positivity suffice for astrocytoma diagnosis 1p19q analysis not essential to exclude oligodendroglioma
3/2018 Diffuse astrocytoma, IDHwt When histological criteria of GBM not fulfilled:CDKN2A/2B deletion or EGFR-amplification or TERT-promotor mutation Prognosis similar to GBM with any of the listed molecular criteria
4/2019 Pediatric diffuse gliomas MYB, MYBL1, or FGFR1 alterations or BRAFV600E mut Brain tumors in children beyond the scope of this article
5/2020 Grading, Arabic numbers Arabic in lieu of Roman numerals
Grading, IDHmut astrocytomas Grade 2: no M, MVP, N, D
Grade 3: M
Grade 3: MVP and/or N and/or D
GBM refers only to IDHwt, H3wt astrocytomas
6/2020 New tumor entities and summary of earlier publications PLNTY (polymorphous low-grade neuroepithelial tumor)
Astroblastoma, MN1-altered
Chordoid glioma, PRKCA D463H-mut
High-grade astrocytoma with piloid features
7/2020 Ependymomas Myxopapillary, WHO Grade 2
Classified according to location and molecular profile
 RELA (C11orf95)-fusion
Posteriuor fossa
 Type A
 Type B
  1. M mitoses, MVP microvascular proliferation, N necrosis, D CDKN2A/B deletions, cIMPACT-NOW consortium to inform molecular and practical approaches to CNS tumor taxonomy, WHO World Health Organization
  2. aSupratentorial excluding subependymoma