Meningioma (benign brain tumour)

What is a meningioma?

A meningioma is a tumour that is almost always benign rather than malignant. This means it doesn’t spread and invade other parts of the body as malignant cancers do.

Benign tumours can cause problems. They can compress vital organs - in the brain, for example, they can squash vital brain tissue. The brain can be surprisingly tolerant, though, and occasionally benign tumours as large as oranges have been found in the brain, which have caused remarkably few symptoms.

However, in certain places, such as around the spinal cord, even tiny benign tumours can be dangerous because they compress vital nerves.

The main risks of a meningioma are:

• Compression causing permanent damage to the brain tissue. Most symptoms get better when the tumour is removed, but occasionally there is irreversible damage.
• Harm caused by symptoms such as fits.
• The risks inherent in treatment, whether from an operation or drugs (there are risks when anyone has a general anaesthetic, for example).
• A risk of haemorrhage during or after surgery, in the area that the tumour was removed from.

Almost all meningiomas are benign, but very occasionally a meningioma can be malignant and spread. They usually grow slowly and can be present for years before causing symptoms.

Symptoms

The symptoms are a result of two factors:

• Interference with the functions controlled by the area of the brain affected by the tumour. This may cause a variety of problems, from muscle weakness and paralysis to changes in behaviour, mood and personality, or problems with speech and memory.
• A general rise of pressure within the skull as the tumour grows in the confined space of this bony box (called raised intracranial pressure). This causes headaches, vomiting and visual problems.

Quite often with a meningioma, the person develops fits or epilepsy.

Causes and risk factors

Many cancers are named after the type of cells from which they're formed. Meningiomas develop from abnormal cells in the meninges, the protective layer that lines the brain and spinal cord, although no one knows why.

Treatment and recovery

Most meningiomas can be completely removed by surgery but, occasionally, radiotherapy is needed. New hormonal treatments are also being tested.