What are children's brain tumours?
A brain tumour is a collection of cells that have grown in an uncontrolled way.
Primary brain tumours are tumours that start in the brain. This is different to cancers that have spread to the brain from somewhere else in the body. These are called:
- secondary brain tumours
- secondary brain cancer
- brain metastases
Secondary brain tumours are rare in children. We have information on secondary brain tumours that you might find helpful. But this information is written for adults with cancer.
Cancerous or non cancerous brain tumours
Benign brain tumours
Benign tumours are non cancerous and usually grow slowly. The cells of the tumour look more like normal cells.
Benign tumours are less likely to spread to other parts of the brain. Your doctor might call some benign brain tumours low grade tumours.
The most common type of benign brain tumour in children is a low grade astrocytoma. You might also hear this called a low grade glioma. This is because astrocytomas develop from glial cells.
Although these tumours are less likely to spread, they can still cause serious symptoms. In some cases they can be life threatening, depending on where the tumour is in the brain.
Malignant brain tumours
Malignant brain tumours are cancerous and grow faster than benign tumours. The tumour cells look very abnormal.
These types of tumours are more likely to come back after treatment and to spread to other parts of the brain. Your doctor might call malignant brain tumours high grade tumours.
The most common types of malignant brain tumours in children include:
- medulloblastoma
- ependymoma
Sometimes it is not possible to say exactly what type of brain tumour it is. This is usually because the tumour is in a part of the brain that is too difficult to take a sample (biopsy) from.
How common is a brain tumour in childhood?
Brain tumours are relatively rare. And they are less common in children than adults.
Tumours affecting the brain and 
are the second most common type of children’s cancer in the UK. Around 420 children are diagnosed with these tumours each year in the UK. They can occur in children of any age.
What causes a brain tumour in childhood?
We don’t know exactly what causes brain tumours in children. Certain genetic conditions can increase a child's risk of developing some types of tumours. But this is very rare. And not every child with these conditions develops a brain tumour.
Some of these genetic conditions include:
- Neurofibromatosis type 1 and type 2 (NF1 or NF2)
- Li-Fraumeni syndrome
- Familial adenomatous polyposis
- DICER1 syndrome
- Nevoid basal cell carcinoma syndrome (Gorlin syndrome)
It’s normal to wonder if there was something you could have done to prevent your child developing a brain tumour. There is no evidence to show that anything anyone does during pregnancy or early in a child’s life could cause a brain tumour.
Symptoms
Brain tumours can start anywhere in the brain. They cause different symptoms depending on their position in the brain.
For example, a tumour in the:
- right side of the brain can cause weakness on the left side of the body
- parietal lobe can affect speech, reading or writing
- occipital lobe can cause sight problems
- cerebellum can affect balance and movement
Please see diagrams below for where the different parts of the brain are.
Brain tumours cause symptoms because they:
- take up space inside the skull when they grow
- block the normal flow of fluid moving through the brain or spinal cord. This can cause pressure known as hydrocephalus.
Children under 4 years old can’t usually describe symptoms such as:
- a headache
- feeling sick
- double vision
So, they might show different symptoms or behaviours than older children even if the tumour is in the same part of the brain.
Some symptoms of a brain tumour are very general. And they could be caused by many other childhood conditions. Although it’s unlikely to be a brain tumour, always get your child’s symptoms checked out by a general practitioner (GP).
The HeadSmart campaign have guidance to help GPs work out with which need a referral.
The brain
To understand tumours that affect the brain and the spinal cord, it helps to know about the:
- parts of the brain and spinal cord
- types of cells and tissues
Here is a short video 3 minute about the different parts of the brain explaining what they do.
What are the different parts of the brain and what do they do?
The brain controls everything we do and how our body functions.
It sends electrical messages along the spinal cord and the nerve fibres to all the parts of our body. The nerve fibres also bring electrical messages back to the brain. The different areas of the brain control the different parts of our body.
The largest part of the brain is called the cerebrum or forebrain. The cerebrum is divided into hemispheres: the left and the right hemisphere. The left hemisphere controls the right part of our body. And the right hemisphere controls the left part. Each hemisphere is further divided into 4 lobes.
The frontal lobe controls our speech, problem solving, movement, personality and sensations. The temporal lobe is where we process sounds and where our memories are stored. The parietal lobe is where touch, temperature and pain is processed. It is where we recognise objects and process information when people speak to us. The occipital lobe processes what we see.
At the back of the brain is the cerebellum or hindbrain. The cerebellum controls our balance, posture and coordination. The lower part of the brain is called the brainstem. It controls functions that we don’t usually think about such as breathing, sneezing, coughing, swallowing and our heartbeat.
In the middle of the brain are the pituitary gland and the pineal gland. The pituitary gland makes hormones that control lots of different body functions such as our growth and the production of sperm and eggs. The pineal gland makes the hormone melatonin which controls our sleep.
Around the brain we have a collection of bones called the skull and membranes called meninges. The meninges support and protect the brain. A clear fluid called cerebrospinal fluid runs between the meninges. The cerebrospinal fluid, or CSF, is made by tissue that lines the brain ventricles. The CSF flows in and around the brain and the spinal cord. It protects them from injuries and provides nutrients.
For more information about the brain, and cancers that affect the brain or spinal cord go to cruk.org/about-brain-tumours
Your brain controls your body by sending electrical messages along nerve fibres. The fibres run out of the brain and join together to make your spinal cord. Together your brain and spinal cord make your central nervous system (CNS).
The main areas of the brain include:
- the cerebrum (forebrain)
- the brain stem
- the cerebellum
The cerebrum (forebrain)
The cerebrum is the largest part of the brain. It's also called the forebrain. It's divided into two halves, the right and left central hemispheres.
These hemispheres control:
- movement
- thinking
- memory
- emotions
- senses
- speech
The nerves that come from the right side of your brain control the left side of your body. And the nerves that control the left side of your brain control the right side of your body.
There are 4 areas to each central hemisphere.
Frontal lobe
The frontal lobe is important for:
- speaking
- planning
- problem solving
- starting some movements
- processing sensations
- part of your personality and character
- emotions and behaviour
Temporal lobe
The temporal lobe is where you process sounds and where you store memories.
Parietal lobe
The parietal lobe recognises objects in the world and stores that knowledge. It's where you receive and process:
- touch
- pressure
- pain
Occipital lobe
This lobe processes what you can see.
The brain stem
This controls body functions we don't usually think about like:
- breathing
- swallowing
- coughing and sneezing
- heartbeat and blood pressure
Making hormones
Your brain makes hormones, which are important for your body to function. The pituitary or pineal gland make these hormones. These two glands are part of the system.
Pituitary gland hormones
These affect:
- growth
- the speed of body processes (your metabolism)
- periods and egg production
- sperm production
Pineal gland hormone
The pineal gland makes melatonin, which controls your sleep patterns.
Fluid around the brain
Fluid called cerebrospinal fluid (CSF) surrounds the brain and spinal cord.
Ventricles are spaces inside the brain filled with CSF. They connect with the space in the centre of the spinal cord and the brain covering (the meninges). This allows the fluid to circulate around and through the brain and spinal cord.
The CSF has some important jobs such as:
- protecting the brain
- supporting the weight of the brain
- maintaining equal pressure around the brain and spinal cord
Treatment
The main treatments for brain tumours in children are:
- surgery
- radiotherapy
- chemotherapy
