Meningioma
What is Meningioma?
A meningioma is a type of tumour that develops in the meninges, the protective layers of tissue surrounding the brain and spinal cord. Most meningiomas are benign (non-cancerous) and slow-growing, but some can be atypical or malignant (cancerous). It is the most common type of primary brain tumour, accounting for about 30% of all brain tumours. Even though a meningioma is not technically a brain tumour, it is included in this category as it can squeeze or compress the adjacent brain, vessels, and nerves.
Meningioma Causes and Risk Factors
The exact cause is unknown, but risk factors include the following:
- Radiation exposure (e.g., prior radiation therapy to the head)
- Genetic mutations (e.g., NF2 gene mutation seen in neurofibromatosis type 2)
- Hormonal factors (linked to higher rates in women; possibly estrogen-related)
Meningioma Symptoms
Symptoms of a meningioma depend on the tumor’s size and location, and may include the following:
- Headaches
- Vision problems
- Seizures
- Loss of smell
- Memory loss
- Weakness or numbness in the limbs
- Hearing loss or ringing in the ears
Meningioma Diagnosis
- Clinical Evaluation: A doctor assesses symptoms such as headaches, vision problems, seizures, or neurological deficits
- Imaging studies
- MRI with contrast to provide detailed images of the tumour’s size, location, and characteristics
- CT scan with contrast for detecting calcifications and bone involvement
- MR spectroscopy (to analyse tumour chemistry)
- PET scans (to evaluate tumour activity)
While most meningiomas are diagnosed based on imaging alone, a biopsy may be required if the tumour’s nature is unclear, helping to confirm the tumour type and grade (benign, atypical, or malignant).
Treatment for Meningioma
The treatment for a meningioma depends on factors such as tumour size, location, growth rate, and symptoms.
- Observation with regular MRI scans is often recommended for small, slow-growing meningiomas that are not causing symptoms.
- Surgical removal is the preferred option if the tumour is symptomatic or growing, with the goal of complete resection whenever possible.
- Radiation therapy and stereotactic radiosurgery (SRS) may be used in cases where the tumour is in a critical location or cannot be fully removed; they can help to slow or stop tumour growth.
- Medications (while not a standard treatment) may be used, such as hormone therapy, chemotherapy, or experimental drugs (e.g., those targeting the NF2 gene mutation). These are reserved for aggressive or recurrent meningiomas not responding to surgery and radiation.
Treatment decisions are individualised based on the patient’s overall health and tumour characteristics, often involving a multidisciplinary team of neurosurgeons, radiation oncologists, and neuro-oncologists.
