Grades of children’s brain tumours
Brain tumours are put into groups according to how quickly they are likely to grow. These are called grades.
To decide on the grade, an expert called a pathologist looks at a sample of the brain tumour. They examine the cells under a microscope. This might be after your child’s:
- biopsy
- surgery to remove some, or all, of the tumour
The more normal the cells look, the lower the grade. The more abnormal the cells look, the higher the grade.
Generally, Grade 1 and 2 tumours are low grade. Grade 3 and 4 tumours are high grade.
The grades are slightly different depending on the type of brain tumour your child has. For example, gliomas range from grade 1 to 4. Ependymomas range from grades 1 to 3. And all embryonal tumours are a grade 4.
Your child’s doctor or nurse can tell you more about the grade of your child’s tumour and what this means for them.
Benign or malignant
Doctors might refer to your child’s low grade tumour as benign. Or a high grade tumour as malignant.
Benign tumours are non cancerous. The cells of the tumour look more like normal cells. These types of brain tumours tend to be:
- relatively slow growing
- less likely to come back after surgery if the tumour is completely removed
- less likely to spread to other parts of the brain or spinal cord
- less likely to need radiotherapy or chemotherapy after surgery
Malignant tumours are cancerous. The tumour cells look very abnormal. These types of brain tumours are more likely to:
- be faster growing
- come back after surgery, even if completely removed
- spread to other parts of the brain and spinal cord
- need radiotherapy or chemotherapy to stop it coming back or to control symptoms
This grading system generally works well for most brain tumours. For some brain tumours, it isn’t as clear as this.
For example, a slow growing benign tumour can cause serious symptoms and be life threatening if it is in a particular part of the brain. Some low grade astrocytomas can spread to other parts of the brain or spinal cord. Although this is rare in children. And radiotherapy and chemotherapy are sometimes used to treat benign tumours.
So, ask your child’s specialist to explain what the grade means for their treatment plan. Treatment also depends on the type of brain tumour they have.
Changing from benign to malignant
Some benign tumours can develop into a malignant tumour. It is called malignant transformation or progression to malignancy. This is very rare in children.
For example, a grade 2 tumour could progress to a grade 3 tumour. Or a grade 3 tumour could change to a grade 4.
Other tests to help grade your child’s brain tumour
Your child’s doctor also looks to see if there are certain 
changes in the cancer cells of some types of brain tumours. This can help grade the brain tumour. It helps your child’s doctor:
- understand the type of brain tumour they have
- work out how quickly it might grow
- work out how likely it will respond to treatment
- make decisions about treatment
Your child’s doctor might call this gene change a or molecular marker.
Doctors in the laboratory measure the level of certain biomarkers. There are a number of different biomarkers. The following is a list of some of the biomarkers your child’s doctor might look for:
- BRAF KIAA 1549 fusion
- BRAF v600e mutation
- TP53
- ATRX
- MYCN
- MYC
- H3-K27 mutation
- IDH-wildtype
- EGFR
- MYB or MYBL1
- FGFR family
- ACVR1
What next?
We have information on the most common types of childhood brain tumours.
