WHO 2016 Classification of gliomas

Area of Science:

• Neuro-oncology
• Pathology
• Molecular Diagnostics

Background:

• Gliomas are primary central nervous system tumors with diverse subtypes.
• Previous classifications relied heavily on histological features.
• The 2016 WHO Classification introduced molecular markers for improved glioma diagnosis.

Purpose of the Study:

• To review the significant changes in glioma classification introduced by the 2016 WHO Classification of CNS Tumours.
• To highlight the impact of molecular markers (IDH mutation, 1p/19q codeletion) on diffuse glioma categorization.
• To discuss newly defined entities and altered classifications within glioma and related tumors.

Main Methods:

• Review of the 2016 WHO Classification of CNS Tumours.
• Analysis of changes in the classification of diffuse and nondiffuse gliomas.
• Discussion of newly introduced entities and revised diagnostic criteria.

Main Results:

• Diffuse gliomas are now primarily classified by IDH mutation and 1p/19q codeletion status.
• The diagnosis of (anaplastic) oligoastrocytoma is expected to decrease significantly.
• New entities include anaplastic pleomorphic xanthoastrocytoma and RELA fusion-positive ependymoma; gliomatosis cerebri is now a growth pattern.

Conclusions:

• The 2016 WHO Classification represents a paradigm shift in glioma diagnosis, integrating molecular pathology.
• This revised classification improves diagnostic accuracy and prognostic stratification for CNS tumors.
• Understanding these changes is crucial for clinicians and researchers in neuro-oncology.