Stagnation and Progression: How Glymphatic Failure Promotes Meningioma Malignancy in Aging

Area of Science:

• Neuroscience
• Oncology
• Geriatrics

Background:

• Meningiomas in the elderly exhibit unusual aggressiveness and peritumoral brain edema (PTBE) despite benign histology.
• Existing hormonal theories do not adequately explain this age-specific malignancy.

Purpose of the Study:

• To propose the "Neuro-Glymphatic-Tumor Axis" as a novel hypothesis for meningioma progression in the elderly.
• To investigate the role of impaired brain clearance mechanisms in meningioma pathogenesis.

Main Methods:

• Review of current literature on meningioma biology, aging, and brain clearance systems.
• Hypothesizing the impact of astrocytic aquaporin-4 (AQP4) polarity loss and meningeal lymphatic atrophy.
• Exploring the consequences of a "hydrodynamic mismatch" on toxin trapping and immune response.

Main Results:

• Senescent collapse of brain clearance infrastructure may drive meningioma progression and PTBE.
• Impaired clearance traps oncogenic toxins (HMGB1, S100A4) and induces "immunological ignorance" via blocked antigen drainage.
• This creates a physically congested and immunologically suppressed tumor microenvironment.

Conclusions:

• The "Neuro-Glymphatic-Tumor Axis" offers a new framework for understanding age-related meningioma behavior.
• Assessing "glymphatic frailty" with functional MRI is a potential diagnostic approach.
• Targeting the tumor microenvironment, including lymphatic-sparing surgery and AQP4 modulation, may combat edema and recurrence.