Meningiomas are tumours that form in the lining or membrane surrounding the brain or spinal cord. Most meningiomas are non-cancerous (benign) and curable. A small proportion are cancerous (malignant) and aggressive, invading the brain and other surrounding structures, and may not be curable.
Meningiomas account for around 25% of primary brain tumours, and most often occur between the age of 40 and 70 years. They are more common in females. Atypical meningiomas are more aggressive than benign meningiomas, and account for around 5% of all meningiomas. Around 4% of meningiomas are malignant.
Meningiomas may cause one or more of the following symptoms:
- seizures (epileptic fits)
- personality or mood changes
- progressive weakness, numbness, or speech disturbance
- confusion or drowsiness
- hearing loss
- nausea and/or vomiting
- visual disturbance
- loss of smell
Sophisticated imaging techniques, including MRI can assist with the diagnosis of meningioma. The only way to make a certain diagnosis of meningioma is by taking a biopsy.
Most meningiomas are treated with surgery, however some require radiotherapy or radiosurgery. Treatment options include:
- Observation with serial MRI scans for smaller tumours, particularly in the elderly
- Surgery, which involves removal of the meningioma by an opening in the skull (craniotomy), offers the best chance of cure, and the lowest risk of recurrence
- Stereotactic radiosurgery
- The prognosis for benign meningiomas is generally very good, particularly where they can be completely removed surgically.
There are several risk factors for developing meningiomas:
- Females are at least twice as likely as men to develop meningioma. Males, however, are more likely to be diagnosed with malignant meningioma.
- Exposure to radiation, including dental x-rays, is associated with a higher incidence of meningiomas.
- The genetic disorder neurofibromatosis type 2 (NF2) is associated with a higher risk of developing meningioma. Individuals with NF2 are also more likely to develop malignant and multiple meningiomas.