[Brain Tumor]

Area of Science:

• Neuropathology
• Molecular Diagnostics
• Neuro-oncology

Background:

• The World Health Organization (WHO) classification is the standard for diagnosing and grading central nervous system tumors.
• The 2016 revision marked a significant shift towards molecularly-based diagnoses, incorporating genetic markers like isocitrate dehydrogenase (IDH) mutations and 1p/19q co-deletion.
• Accurate diagnosis now requires integrating both histological and molecular findings.

Purpose of the Study:

• To provide a practical approach for the differential diagnosis of diffuse small-cell glioma in adults.
• To highlight the importance of selecting appropriate genetic testing methods.
• To aid clinicians in understanding the diagnostic criteria outlined in the latest WHO classification.

Main Methods:

• Focuses on the differential diagnosis of diffuse small-cell gliomas.
• Emphasizes the integration of neuropathological and molecular diagnostic techniques.
• Discusses the selection of suitable genetic testing for accurate tumor classification.

Main Results:

• The 2016 WHO classification incorporates new entities defined by molecular features.
• Accurate diagnosis of diffuse gliomas relies on a combination of microscopic examination and molecular testing.
• Understanding these integrated diagnostic criteria is crucial for effective patient management.

Conclusions:

• The shift to molecularly-oriented diagnoses in the 2016 WHO classification necessitates updated diagnostic strategies.
• Accurate diagnosis of adult diffuse gliomas requires expertise in neuropathology, neuro-oncology, and molecular genetics.
• This text offers a practical guide to navigating these diagnostic complexities.