High grade glioma
High grade gliomas are malignant (cancerous) tumours that develop from brain cells called astrocytes. Astrocytomas are the most common type of glioma. You will often hear the terms astrocytoma and glioma used interchangeably.
In children, only 20% of astrocytomas are high grade. High grade gliomas are classified according to the grade of aggressiveness (how quickly they grow) as either anaplastic astrocytomas (grade III) or glioblastoma multiforme (GBM).
These tumours often spread into the healthy tissue that surrounds the tumour. This makes them difficult to remove surgically. They most commonly arise in the cerebral hemispheres (frontal, parietal and temporal lobes) or centre of the brain (thalamus). The tumour can spread to other parts of the brain and spinal cord.
Who gets a high grade glioma?
Less than 30 children a year develop high grade glioma in the UK. This is about 8% of all childhood brain and spinal cord tumours. High grade gliomas are the most common type of adult brain tumour and although they look the same under the microscope, they may be different biologically.
Like most brain tumours the cause of high grade gliomas is unknown.
Signs and symptoms
The symptoms depend on where in the brain the tumour is and also whether there is increased pressure in the head (raised intracranial pressure).
- nausea and vomiting (most common)
- lethargy and irritability
- seizures (fits)
- difficulty with tasks like handwriting
- gradual decline in school work
- changes in personality and behaviour
- abnormal gait (the way the child walks).
If the tumour spreads or is located in the spinal cord, the signs and symptoms may include:
- back pain
- difficulty walking
- problems with bowel and bladder control.
Tests / investigations
We will need to carry out some tests to find out as much as possible about the type, position and size of the tumour. This will help us to decide on the best treatment for your child. These tests include:
- CT scan – it is likely a CT scan of your child’s brain was the first specific test carried out at your local hospital. Although MRI scans are usually the best way of seeing the tumour and the effects of treatment, sometimes CT scans are also useful.
- MRI scan – this scan allows us to see the brain and spine in great detail and is used regularly to diagnose and follow the effect treatment is having on your child’s tumour.
Staging is a measure of how far the tumour has spread beyond its original site. It is important to know in high grade glioma whether the tumour can be completely removed. This is rarely possible. Occasionally the tumour can spread to the cerebrospinal fluid (CSF) and spine.