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Macmillan and Cancerbackup merged in 2008. Together we provide free, high quality information for people affected by cancer through our publications, website and phone service. Find out more|.
Find out how we produce our information|
This information is about a specific type of brain tumour called a medulloblastoma, which mainly affects children. It should ideally be read with our general information about brain tumours|.
This section has information about medulloblastoma in children. You may also like to read our section about children's cancers|.
If you are an adult with medulloblastoma, most of the information will still be relevant to you.
Cells within the brain normally grow in an orderly and controlled way, but if for some reason this order is disrupted, the cells continue to divide and form a lump or tumour.
A tumour is either benign or malignant. Benign tumours can continue to grow, but the cells do not spread from the original site. In a malignant tumour, the cells can invade and destroy surrounding tissue and may spread to other parts of the brain.
Medulloblastomas are malignant tumours formed from poorly developed cells at a very early stage of their life. They develop in the cerebellum (see diagram below) in a part of the skull called the posterior fossa, but may spread to other parts of the brain.
Side view of the head
View a large copy of the diagram of the side view of the head|
Very rarely, medulloblastomas may spread to other parts of the body. If they do spread to other parts of the brain or to the spinal cord, this is usually through the cerebrospinal fluid (CSF). CSF is the fluid that surrounds and protects the brain and the spinal cord.
Tumours affecting the central nervous system (CNS), which is made up of the brain and spinal cord, are fairly rare. About 4,500 new tumours are diagnosed each year in the UK. Many of these are malignant.
Medulloblastomas are more common in children, particularly between the ages of three and eight. They make up about 1 in 5 (20%) of all childhood brain tumours. The tumour is more common in boys than girls. They rarely occur in adults.
As with most brain tumours, the cause of medulloblastoma is unknown. Researchers| are trying to discover possible causes.
The first symptoms of any brain tumour are usually due to increased pressure within the skull (raised intracranial pressure).
This may be caused by a blockage in the ventricles (fluid-filled spaces in the brain), which leads to a build-up of CSF. The increased pressure can also be caused by swelling around the tumour itself.
Raised intracranial pressure can cause headaches, sickness (vomiting|) and sight problems. Vomiting is common first thing in the morning. Children often appear tired, weak and irritable. Changes in personality and behaviour may also be noticed.
As the cerebellum is the part of the brain that controls muscle coordination, a tumour in this area may cause problems with walking. A person may appear to stumble, or walk in an awkward or uncoordinated way. Speech can also be affected, and words may be slurred or muddled.
Other specific symptoms associated with medulloblastoma are nystagmus (jerky eye movements), stiffness in the neck, and muscle weakness. The symptoms that people have will depend on the size and position of the tumour.
Your child's doctors need to find out as much as possible about the type, position and size of the tumour, so they can plan treatment. Your child may have a number of tests and investigations.
A doctor will carry out a thorough examination and test the power and feeling in the arms and legs, and their reflexes.
Your doctor will look into the back of your child's eyes using an ophthalmoscope. They can see if the optic nerve at the back of the eye is swollen. This can be caused by oedema (swelling of the tissues within the brain), which may occur due to an increase in the amount of fluid in the brain.
A CT scan takes a series of x-rays that build up a three-dimensional picture of the inside of the body. The scan is painless and takes 10-30 minutes. CT scans use small amounts of radiation, which will be very unlikely to harm your child or anyone they come into contact with. Your child will be asked not to eat or drink for at least four hours before the scan. A CT scan may be used to identify exactly where the tumour is or to check for any spread of the cancer.
Most people who have a CT scan are given a drink or injection to allow particular areas to be seen more clearly. This may make your child feel hot all over. Before having the injection or drink, it is important to tell the person doing this test if your child is allergic to iodine or has asthma.
This test is similar to a CT scan but uses a strong magnetism instead of x-rays to build up cross-sectional pictures of your child's body.
Before having the scan you'll be asked to remove any metal belongings including jewellery from your child. Some people are given an injection of dye into a vein in the arm. This is called a contrast medium and can help the images from the scan show up more clearly. During the test your child will be asked to lie very still on a couch inside a long cylinder (tube) for about 30 minutes. It is painless but can be slightly uncomfortable, and some people feel a bit claustrophobic during the scan. It's also noisy, but your child can listen to a CD or wear earplugs.
To give an exact diagnosis, a sample of cells from the tumour (biopsy) is usually taken and examined under a microscope. The biopsy involves an operation. The doctor will discuss with you whether this is necessary and exactly what the operation involves.
The test known as a lumbar puncture| is carried out to see if there are any tumour cells present in the cerebrospinal fluid (CSF). The skin on your child's back is numbed with local anaesthetic, and a hollow needle is inserted between two of the spinal bones and into the spinal canal. A small amount of spinal fluid can be withdrawn for tests. MRI scans can also show the presence of any tumour in the spinal cord.
The treatment for medulloblastoma depends on a number of factors, including your child's general health, and the size and position of the tumour. The results of the tests will enable the doctor to decide on the best type of treatment.
Your child's treatment will usually be planned by a team of specialists known as a multidisciplinary team (MDT|). The team will usually include:
There are some risks associated with treatment to the brain and the doctor will discuss these with you.
Before you have any treatment, your doctor will give you full information about the aims of the treatment and what it involves. They will usually ask you to sign a form saying that you give your permission (consent|) for the hospital staff to give the treatment to your child. No medical treatment can be given without your consent.
Treatment can be given for different reasons and the potential benefits will vary for each child. If your child has been offered treatment that aims to cure the cancer, deciding whether your child has the treatment may not be difficult. However, if a cure is not possible and the treatment is to control the cancer for a period of time, it may be more difficult to decide whether to go ahead.
If you feel that you can’t make a decision about the treatment| when it is first explained, you can always ask for more time to decide.
The treatment is often given at an important time in a child's development. There may be some long-term effects of treatment for medulloblastoma, including hearing problems, growth and hormonal changes, behavioural changes and possible learning difficulties. The doctor will discuss the possible long-term effects with you before treatment.
If your child has raised intracranial pressure, steroid drugs| may be given to reduce swelling around the tumour. At the beginning of the operation a tube (shunt) may need to be inserted to drain off the excess fluid. Alternatively, a minor operation may be done to allow fluid to drain away. This operation is known as a third ventriculectomy. In either case a small flat plastic bubble (ommaya reservoir) may be inserted under the scalp. The device can be used to give chemotherapy treatment into the fluid around the spinal cord.
The aim of surgery| is to remove as much of the tumour as possible, without damaging the surrounding brain tissue. It is rarely possible to remove the tumour completely, so surgery will be followed up with radiotherapy and/or chemotherapy.
After surgery for medulloblastoma, a CT scan or MRI scan may be done to find out how much of the tumour is left.
Radiotherapy| treatment uses high-energy rays to destroy the cancer cells and is commonly used after surgery to destroy any remaining malignant cells. As medulloblastoma may spread through the CSF to the spinal cord, radiotherapy is given to the brain and spinal cord.
Whenever possible, radiotherapy is not given to children under the age of three to allow further development of the brain and spinal cord, and to reduce the risk of long-term side effects. Instead, a course of chemotherapy is given and, if necessary, radiotherapy is given when the child is older.
We have more information about radiotherapy for children with head and neck cancers|.
Chemotherapy| is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. It may be given alone to treat medulloblastoma, or with surgery and radiotherapy.
Having a child diagnosed with cancer is an extremely stressful time for the whole family. You may experience many different emotions| including anxiety|, anger| and fear. These are all normal reactions, and are part of the process many people go through in trying to come to terms with the siuation.
Family members and close friends can offer support. Many people find it helpful to talk things over with the doctor or nurse, or one of our cancer support specialists|. There are also many organisations| who provide information and support to children with cancer, and their families.
In some circumstances, adults with a medulloblastoma may not be allowed to drive for a period of time.
After surgery to the main part of the brain (the cerebrum) there is a small risk of epileptic fits. The Drivers and Vehicle Licensing Association (DVLA) requires that you do not drive for at least a year after this type of surgery.
You may not be allowed to drive some types of vehicles, such as an LGV (large goods vehicle) or a PCV (passenger carrying vehicle). You may not be able to drive them for at least five years after treatment and will only be able to after this time if your cancer has not come back.
The hospital will not contact the DVLA. It is your responsibility to do so and your doctor will advise you how to do this. You can contact the DVLA by phone on 0300 790 6806 or at dvla.gov.uk|
Children treated for a medulloblastoma will normally be allowed to drive from the age of 17. They can hold a full licence until 70, unless there are ongoing medical problems associated with their tumour or treatment such as epilepsy.
This section is based on our medulloblastoma fact sheet and has been compiled using information from a number of reliable sources, including:
For answers, support or just a chat, call the Macmillan Support Line free (Monday to Friday, 9am-8pm)
If you have any questions about cancer, need support or just want someone to talk to, ask Macmillan.