Advances in Central Nervous System Tumor Classification.

Area of Science:

• Neuro-oncology
• Genomics
• Pathology

Background:

• Traditional central nervous system (CNS) tumor classification relied on histology.
• The molecular era necessitates integrating intrinsic tumor biology into diagnostics.
• The 2021 World Health Organization (WHO) classification reformulates CNS tumor diagnosis using molecular parameters.

Purpose of the Study:

• To present updated knowledge on CNS tumor classification in the molecular era.
• To highlight the impact of molecular alterations on meningioma classification and management.
• To emphasize the need for a multidisciplinary approach including molecular data.

Main Methods:

• Review of current literature on CNS tumor classification.
• Analysis of the 2021 WHO classification criteria for meningiomas.
• Discussion of molecular markers (e.g., CDKN2A/B loss, TERT promoter mutation) in meningioma grading.

Main Results:

• The 2021 WHO classification incorporates molecular features for defining CNS tumor types.
• Meningiomas are classified into 15 variants, with molecular criteria now included for grading.
• Homozygous loss of CDKN2A/B and TERT promoter mutation are key molecular markers for WHO grade 3 meningioma.

Conclusions:

• Integrated molecular and histologic data provide a more precise classification of CNS tumors.
• Molecular profiling is crucial for accurate meningioma grading and predicting tumor behavior.
• Future classification and clinical management of meningiomas will increasingly rely on molecular insights.