Malignant Meningiomas: From Diagnostics to Treatment

Area of Science:

• Neuro-oncology
• Pathology
• Genetics

Background:

• Meningiomas represent 40% of primary brain tumors; grade 3 (anaplastic) meningiomas are rare (1.5%) but aggressive.
• Diagnosis relies on histopathology and molecular markers, guided by the World Health Organization (WHO) Classification of Tumors of the Central Nervous System (CNS).
• Grade 3 meningiomas exhibit malignant cytomorphology, high mitotic activity, and specific genetic alterations (TERT promoter mutation, CDKN2A/B deletion).

Purpose of the Study:

• To summarize the diagnostic criteria, treatment, and prognosis of grade 3 meningiomas.
• To highlight the challenges in managing these aggressive tumors.

Main Methods:

• Review of current literature and diagnostic criteria based on the WHO CNS tumor classification.
• Analysis of treatment modalities including surgery, radiotherapy, and emerging systemic therapies.
• Evaluation of recurrence rates and survival data for grade 3 meningiomas.

Main Results:

• Grade 3 meningiomas are characterized by anaplasia, elevated mitotic activity, and specific genetic markers.
• Surgery and radiotherapy are the primary treatments, with limited data on radiosurgery and systemic therapies.
• High recurrence rates (50-95%) and poor survival rates (5-year: 66%, 10-year: 14-24%) are observed despite optimal management.

Conclusions:

• Grade 3 meningiomas are aggressive tumors with a dismal prognosis and high recurrence rates.
• Further research into novel therapeutic strategies, including stereotactic radiosurgery and systemic therapy, is urgently needed.
• Improved understanding and management are critical to enhance survival outcomes for patients with anaplastic meningiomas.