The membranes around the brain and spinal cord are called ‘meninges'. Meningiomas are therefore tumours that form typically from the meningeal layers, but occasionally, they can form in other places, such as the cerebrospinal fluid spaces, such as the ‘ventricles’. Meningiomas can affect the brain by exerting pressure on surrounding brain tissue, nerves or blood vessels in the brain. The majority of meningiomas is benign (i.e. non-cancerous) and may grow slowly over many years. Meningiomas can remain silent and may not produce any symptoms until there is pressure on sensitive brain and nerve structures. Meningiomas are more common in women and older people.
The exact cause of meningioma is unknown, but there are several associated factors:
- Hereditary factors.
- Neurofibromatosis (Type 1 and Type 2).
- Radiation exposure, including previous radiotherapy.
- Gender - women are more affected by meningioma than men, and this is thought to be connected to female hormones.
As with many types of brain tumours, symptoms will often depend on the area of the brain affected. Common symptoms of meningioma include…
- Headaches (particularly if these become progressively worse over time).
- Seizures and / or weakness or numbness in the arms or the legs.
- Vision issues, including seeing double vision, blurred vision, or loss of peripheral vision.
- Tinnitus (ringing in the ears) or hearing loss.
- Alteration or loss of sense of smell.
- Loss of memory.
Tests / Diagnosis
Symptoms of meningioma can sometimes be hard to identify and can be confused with normal aging. Diagnosis of a meningioma is usually suspected based on typical features on CT (computed tomography) or MRI (magnetic resonance imaging) scan of the head. However, the diagnosis of a meningioma is definitively determined by laboratory analysis (histopathology) of tissue samples sent during surgical removal.
Depending on the location and size of the meningioma, treatment options include:
- Observation – Further CT or MRI scans will be performed to monitor growth of meningiomas.
- Surgery – Surgery may be performed to remove or reduce the size of the meningioma. A biopsy sample is sent during surgery to confirm the type and grade of meningioma. Wherever possible, complete removal is associated with best long-term outcome.
- Radiotherapy / radiosurgery – This may be offered alone, or as additional treatment to surgery, for meningiomas that: (i) cannot be operated upon, (ii) are high-grade; or (iii) grows back after treatment.