A benign (non-cancerous) brain tumour is a mass of cells that grows slowly in the brain. It usually stays in one place and does not spread.
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. Grade 1 tumours are the least aggressive and grade 4 are the most harmful and cancerous. Cancerous tumours are described as malignant.
Low-grade brain tumours – grades 1 or 2 – tend to be slow growing and unlikely to spread, so they're usually classed as benign.
Read about high-grade (malignant) tumours.
What are the symptoms?
The symptoms of a low-grade or benign brain tumour depend on how big it is and where it is in the brain. Some slow-growing tumours may not cause any symptoms at first.
Eventually, the tumour can put pressure on the brain and may cause headaches and seizures (fits). The tumour can also prevent an area of the brain from functioning properly. For example, a tumour in the occipital lobe (at the back of the brain) may cause loss of vision on one side. See Benign 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 (tumours that start in the brain). About 20% of these are low-grade gliomas, a type of tumour that starts in the supportive tissue of the brain. Doctors don't know what causes these.
See Benign brain tumour - causes for information about the possible causes of other types of benign brain tumour.
Treatment and outlook
Benign brain tumours can be serious if they are not diagnosed and treated early. Although they remain in one place and do not usually spread, they can cause harm by pressing on and damaging nearby areas of the brain.
Many benign brain tumours can be surgically removed and don't come back once they have been removed, causing no further problems. However, grade 2 gliomas will often grow back after treatment and have the potential to change into high-grade or malignant (cancerous) tumours, which are fast-growing and likely to spread. This change is called mutation.
See Benign brain tumour - treatment for more information on your treatment options.
In summary, your treatment will depend on the type and location of the tumour, and your outlook will depend on whether the tumour grows back and whether it mutates (changes).
