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Diagnostic Testing for Diffuse Gliomas


Diffuse gliomas are the most common primary brain tumors, affecting approximately 15,000 people in the US each year. These tumors are uniformly fatal, but have widely variable clinical courses and treatment approaches that are often predicted by their molecular profile. While diagnostic molecular characterization of these tumors is now possible in modern molecular pathology labs, there is wide variability in the genetic alterations that are tested as well as the methods for detection. The World Health Organization (WHO) provides standardization for diagnostic classes of diffuse gliomas, including their molecular definitions, but there are currently no clinical practice guidelines that address molecular testing more broadly for diffuse gliomas.


To assess evidence related to the optimal diagnostic testing for pediatric and adult patients with diffusely infiltrative gliomas in order to provide guidance for improved diagnosis, prognosis, and prediction.

Key Questions

Overarching Question: What ancillary tests are needed to classify diffuse gliomas and sufficiently inform the clinical management of patients?

1a.  What genetic and molecular alterations should be included for optimal classification of:

  • Diffuse astrocytoma                         
  • Oligodendroglioma
  • Oligoastrocytoma
  • Glioblastoma
  • Anaplastic astrocytoma
  • Anaplastic oligodendroglioma                         
  • Anaplastic oligoastrocytoma  
  • Diffuse midline glioma                        

1b. What are the acceptable techniques/methods for mutation testing of diffuse glioma? What are the expected turn-around-times for individual assays?

1c. What are the acceptable techniques/methods for assessing whole genome copy number alterations?

2. What are the core molecular tests/findings that provide sufficient classifying information in the setting of discreet clinicopathologic entities?

3. What are the acceptable techniques/methods/criteria for determining MGMT promoter methylation status?


Research and review.


American Association of Neuropathologists                     

American Society of Clinical Oncology                     

Association of Molecular Pathology

Society for Neuro-Oncology

Panel Members

Daniel J. Brat, MD, PhD, FCAP, Chair 

Kenneth Aldape, MD 

Peter Canoll, MD, PhD 

Meera R. Hameed, MD, FCAP 

Brent Harris, MD, PhD, FCAP 

Eyas M. Hattab, MD, MBA, FCAP 

Michelle Hawks, BA 

Jason T. Huse, MD, PhD 

Dolores Lopez-Terrada, MD, PhD, FCAP 

Robert B. Jenkins, MD, PhD, FCAP 

Julia Bridge, MD, FCAP 

Howard Colman, MD, PhD 

William McDonald, MD, FCAP 

Arie Perry, MD, FCAP 

Fausto Rodriguez, MD 

Martin J. Van Den Bent, MD, PhD 

Lesley Souter, PhD 

Carol Colasacco, MLIS, SCT(ASCP) 

Nicole E. Thomas, MPH, CT(ASCP) 

Additional Information

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