What are brain tumours?

Brain tumours are collections of abnormal cells that grow out of control either within the brain itself or in the layers of tissues that cover the brain. The symptoms they produce depend on the area of the brain in which they arise; survival, and whether or not they can be treated, depends partly on this and also on the type of cells that give rise to the tumour.

What causes brain tumours and who is at risk?

There are no well-established risk factors for brain tumours; reports of a link between mobile phones and brain tumours are a matter of considerable controversy and the link has not been confirmed.

There are two main types of brain tumours: gliomas and meningiomas.

Gliomas

Many gliomas, but not all, are malignant (cancerous). Gliomas may grow to a considerable size before any symptoms are noticed.

Headaches are an early symptom in about one-third of patients. The headaches may occur at night, waking the patient from sleep, and they may be worse first thing in the morning. Vomiting is a frequent accompanying symptom. Dizziness may also occur. The other major symptom of a glioma is fits.

Meningiomas

Meningiomas are benign tumours and are usually very slow growing. They may attain considerable size before they cause any noticeable symptoms.

The symptoms they produce are just as diverse as those of gliomas and may also include personality changes, gradual loss of vision in one eye, double vision and occasionally headaches.

Pituitary tumours

Most pituitary tumours are benign. They may produce some loss of vision, which is frequently not noticed by the patient. Other effects are often due to hormones produced by the tumour. These effects may include secretion of milk from the nipples, infertility, increase in size of hands and feet with overgrowth of the lower jaw or high blood pressure, obesity and diabetes, depending on which hormones are being produced in excess.

How do doctors recognise brain tumours?

A diagnosis is made by performing a brain scan, either by computerised tomography (CT), which uses X-rays, or magnetic resonance imaging (MRI), which uses magnetic fields (see separate Factsheets). These scans will often give useful information about the tumour type. It will also be necessary to perform a brain biopsy to remove a small sample of the tumour to confirm the diagnosis.

What is the treatment for brain tumours?

Malignant brain tumours

Malignant tumours are usually treated by a combination of surgery and radiotherapy (cancer-killing X-rays), sometimes with chemotherapy (cancer-killing drugs) as well. Because these tumours frequently spread into surrounding normal brain, it is usually not possible to cut out the tumour completely.

Benign brain tumours

Benign brain tumours, including meningiomas, grow more slowly than malignant tumours. Complete surgical removal and therefore cure is often achievable. Radiotherapy is occasionally given for a benign glioma when the tumour is compressing a part of the brain and producing symptoms.

Pituitary tumours can often be completely removed by surgery, and some can be shrunk with tablets.