Acta Neuropathologica

, Volume 135, Issue 4, pp 639–642 | Cite as

cIMPACT-NOW update 2: diagnostic clarifications for diffuse midline glioma, H3 K27M-mutant and diffuse astrocytoma/anaplastic astrocytoma, IDH-mutant

  • David N. LouisEmail author
  • Caterina Giannini
  • David Capper
  • Werner Paulus
  • Dominique Figarella-Branger
  • M. Beatriz Lopes
  • Tracy T. Batchelor
  • J. Gregory Cairncross
  • Martin van den Bent
  • Wolfgang Wick
  • Pieter Wesseling


The major changes in brain tumor classification arise through the World Health Organization (WHO) classification update process. To provide possible guidelines for practicing diagnosticians between WHO updates and to facilitate future WHO classification updates, cIMPACT-NOW (the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy—Not Official WHO) was established. Since its creation in 2016, cIMPACT-NOW (cIMPACT for short) has convened three working committees to address ongoing classification and grading challenges. In addition to addressing questions about the use of the NOS (Not Otherwise Specified) suffix, Working Committee 3 clarified diagnostic criteria for the following entities: Diffuse midline glioma, H3 K27M-mutant; diffuse astrocytoma, IDH-mutant; and anaplastic astrocytoma, IDH-mutant. The present correspondence reports the recommendations of cIMPACT Working Committee 3 clarifying diagnostic criteria for these entities.

Diffuse midline...



This paper has been reviewed by the Steering Committee and Clinical Advisory Panel of cIMPACT-NOW [7, 8] and by the International Society of Neuropathology Executive.


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • David N. Louis
    • 1
    Email author
  • Caterina Giannini
    • 2
  • David Capper
    • 3
  • Werner Paulus
    • 4
  • Dominique Figarella-Branger
    • 5
  • M. Beatriz Lopes
    • 6
  • Tracy T. Batchelor
    • 7
  • J. Gregory Cairncross
    • 8
  • Martin van den Bent
    • 9
  • Wolfgang Wick
    • 10
    • 11
    • 12
  • Pieter Wesseling
    • 13
    • 14
  1. 1.Department of PathologyMassachusetts General Hospital and Harvard Medical SchoolBostonUSA
  2. 2.Department of Laboratory Medicine and PathologyMayo ClinicRochesterUSA
  3. 3.Department of Neuropathology, Berlin Institute of HealthCharité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu BerlinBerlinGermany
  4. 4.Institute of NeuropathologyUniversity Hospital MünsterMünsterGermany
  5. 5.Aix-Marseille Univ, APHM, CNRS, INP, Inst Neurophysiopathol, Hôpital de la Timone, Service d’Anatomie Pathologique et de NeuropathologieMarseilleFrance
  6. 6.Departments of Pathology and Neurological SurgeryUniversity of VirginiaCharlottesvilleUSA
  7. 7.Departments of Neurology, Radiation Oncology and Division of Hematology/OncologyMassachusetts General Hospital and Harvard Medical SchoolBostonUSA
  8. 8.Charbonneau Cancer InstituteUniversity of CalgaryCalgaryCanada
  9. 9.The Brain Tumor Center at Erasmus MC Cancer CenterRotterdamThe Netherlands
  10. 10.Neurology Clinic and National Center for Tumor Diseases (NCT)University Hospital HeidelbergHeidelbergGermany
  11. 11.Clinical Cooperation Unit NeurooncologyGerman Cancer Research Center (DKFZ)HeidelbergGermany
  12. 12.German Cancer Consortium (DKTK) Core Center HeidelbergHeidelbergGermany
  13. 13.Department of PathologyVU University Medical CenterAmsterdamThe Netherlands
  14. 14.Department of Pathology, Princess Máxima Center for Pediatric OncologyUniversity Medical Center UtrechtUtrechtThe Netherlands

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