A meningioma is a benign, slow-growing brain tumour arising from the meninges or the arachnoid area. Meningiomas can develop anywhere that arachnoid cells are found. These are found not just in the brain, but also along the spinal cord canal, for example.
Only rarely (in around 1.7 per cent of cases) can meningiomas become malignant or grow faster than normal. Meningiomas account for around 15 per cent of all brain tumours. Usually meningiomas are completely removed through surgery, although further meningiomas can develop after the operation.
In most cases, meningiomas develop at around the age of 45. They affect women more commonly than men. Only two per cent of cases are seen in children and adolescents.
Depending on their size and location, meningiomas can cause symptoms such as headache, nausea, vomiting, visual disturbances, olfactory (smell) disturbances and sensitivity problems, reduced power, seizures or epilepsy. As a result of their slow growth and the brain's ability to adapt, many meningiomas grow for some time before the patient experiences any symptoms.
With the aid of magnetic resonance imaging (MRI) or angiography, these tumours are easily diagnosed.
The aim of treatment is to completely remove the meningioma through microsurgery, which is often accomplished. Usually, this is performed in a meningioma operation carried out via a craniotomy (opening of the skull). Larger meningiomas must first be shrunk from within and then removed.
If the tumour is completely removed through surgery and if the tumour tissue is benign, no further treatment is required. In these instances, follow-up CT or MRI scans will be carried out. If parts of the tissue remain or if the meningioma is malignant, chemotherapy, stereotactic (gamma knife) or conventional fractionated radiotherapy as well as accompanying medication-based therapy may be considered.
Around ten per cent of meningiomas continue to grow again despite being completely removed during meningioma surgery. If only partially removed, they grow back again in around 80 per cent of cases.