Brain tumours are put into groups according to how quickly they are likely to grow. There are 4 groups, called grades 1 to 4.
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:
- 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.
Grade 1 and 2 tumours are low grade. Grade 3 and 4 tumours are high grade.
Benign or malignant
Doctors might refer to your child’s low grade tumour as benign. Or a high grade tumour as malignant.
Benign 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 more likely to:
- be relatively 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 the tumour 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.
For example, a grade 2 tumour could progress to a grade 3 tumour. Or a grade 3 tumour could change to a grade 4.
We have information on the most common types of childhood brain tumours.