Meningioma of Uncertain Behavior
Overview
Meningiomas are tumors arising from the meninges, the membranes that surround the brain and spinal cord. Meningiomas of uncertain behavior represent a diagnostic challenge, falling between benign (WHO grade I) and malignant (WHO grade III) classifications, often referred to as atypical meningiomas (WHO grade II) 1. These tumors have a higher risk of recurrence and progression compared to benign meningiomas.Diagnosis
Diagnosis is based on histopathological examination of tumor tissue 1.
WHO grade II (atypical meningioma) is characterized by increased cellularity, a high mitotic index, and/or specific cytologic features such as a high nuclear-to-cytoplasmic ratio, prominent nucleoli, and sheeting or whirling of cells 1.
Further diagnostic evaluation may include imaging studies such as MRI or CT scans to assess tumor size, location, and involvement of surrounding structures 1.Management
Surgical resection is the primary treatment modality for meningiomas of uncertain behavior 1. The extent of resection (gross total versus subtotal) influences prognosis and recurrence rates 1.
Adjuvant radiotherapy is often considered, particularly for incompletely resected tumors or those with higher-grade features, to reduce the risk of recurrence 1.
Observation may be an option for small, asymptomatic tumors with minimal features of uncertain behavior, especially in elderly or medically frail patients 1.Key Recommendations
Surgical resection is the cornerstone of management for meningiomas of uncertain behavior 1. (Evidence: Moderate)
Adjuvant radiotherapy should be considered for incompletely resected meningiomas of uncertain behavior to decrease recurrence rates 1. (Evidence: Moderate)
Close follow-up with serial imaging is recommended after treatment to monitor for recurrence or progression 1. (Evidence: Expert opinion)References
1 Davidson B, Eapen-John D, Mithani K, Rabin JS, Meng Y, Cao X et al.. Lesional psychiatric neurosurgery: meta-analysis of clinical outcomes using a transdiagnostic approach. Journal of neurology, neurosurgery, and psychiatry 2022. link