A malignant brain tumour is a fast-growing cancer that spreads to other areas of the brain and spine.
Most malignant brain tumours are secondary cancers, which means they started in another part of the body and spread to the brain. Primary brain tumours are those that started in the brain.
There are different types of malignant brain tumour, depending on the type of brain cells they have grown from. The most common type is a glioma, which accounts for more than half of all primary brain tumours.
Generally, brain tumours are graded from 1 to 4 according to their behaviour, such as how fast they grow and how likely they are to spread. A malignant brain tumour will be either grade 3 or 4, whereas grade 1 or 2 tumours are usually classed as benign or non-cancerous brain tumours.
What are the symptoms?
The symptoms of a malignant brain tumour depend on how big it is and where it is in the brain.
The tumour can put pressure on the brain and may cause headaches and seizures (fits). It can also prevent an area of the brain from functioning properly. See Malignant brain tumour – symptoms for more information.
Who is affected?
Brain tumours can affect people of any age, including children.
There are about 4,500 new cases of primary brain tumours in the UK each year. The exact cause of these is unknown, although an underlying genetic disease, such as neurofibromatosis, can increase your risk of developing one (see Malignant brain tumour – causes for more information).
Treatment and outlook
A primary malignant brain tumour must be treated as soon as possible because it can spread to and damage other parts of the brain and spinal cord.
The tumour is usually operated on and as much of it removed as possible. This may be followed with chemotherapy and radiotherapy. However, malignant tumours will often return.
The outcome for malignant primary brain tumours depends on many factors, such as the type and location of the tumour and how ill you were when diagnosed. For more information, go to Cancer Research UK’s page on Statistics and outlook for brain tumours.
Secondary brain tumours are serious as they have already spread throughout the body. Treatment aims to improve symptoms and prolong life.
For more information on the treatment options, see Malignant brain tumour – treatment.