Glioma is the name of a family of brain tumours, not one single diagnosis. The term covers several tumour types that develop from glial cells in the brain, and can range from low-grade, slow-growing forms to high-grade, aggressive disease. That matters because words such as glioblastoma, astrocytoma and oligodendroglioma do not describe the same condition. They describe different tumour types, and those differences can affect symptoms, prognosis, and treatment decisions.
What is a glioma?
A glioma is a type of brain tumour that develops from cells that should be healthy support cells in the brain. These support cells are called glial cells and include astrocytes, oligodendrocytes and ependymal cells.
Different tumours within this family develop from different glial cell types and behave in different ways. Different glioma tumour types include:
· Glioblastoma
· Astrocytoma
· Oligodendroglioma
· Paediatric-type diffuse high-grade –glioma (including diffuse intrinsic pontine glioma, DIPG)
· Ependymoma
Glioma tumours are also often categorised by their ‘grade’ – a way of describing how fast a tumour grows and whether the cells that make up the tumour are cancerous or not.
What do glioma grades mean?
Glioma grade helps describe how the tumour is expected to behave.
Grade 1 gliomas are usually the slowest-growing and often occur in children and teenagers. They are less likely to spread into the brain compared to higher grade tumours. Grade 2 tumours are also low-grade, but they have a greater risk of returning following treatment or progressing to a higher grade over time.
Grade 3 tumours are high-grade and cancerous. They grow more quickly and can spread to other parts of the brain or spinal cord. They are also more likely to recur after treatment. Grade 4 tumours are the fastest-growing gliomas and nearly always return after treatment.
Why do subtype and grade matter?
These classifications matter because they help explain how quickly a tumour may grow, how likely it is to return, which treatment approaches may be considered and why one diagnosis can look very different from another.
What symptoms can these tumours cause?
Symptoms can vary significantly between patients, depending on the tumour’s location, size and growth rate.
Common brain tumour symptoms include persistent headaches (usually worse in the morning), seizures, nausea and vomiting, vision problems, cognitive or personality changes, and weakness or numbness on one side of the body.
The exact symptoms a patient may experience depends on where the tumour grows, its size, how aggressive it is and which part of the brain it affects.
How are these tumours treated?
Treatment depends on the type of tumour, its grade, its location in the brain and the patient’s overall health.
Surgery is often the first step and is used to remove as much of the tumour as possible while preserving brain function. Radiotherapy may be used after surgery to destroy any remaining tumour cells and reduce the risk of recurrence. It can also be used when surgery is not possible.
For higher grade tumours, chemotherapy is often used following surgery and in conjunction with radiotherapy.
Different tumour types and grades can follow very different treatment pathways.
Why does research into different tumour types matter?
Research matters because this is not one condition with one treatment pathway. It is a broad family of tumours with important biological differences.
We support long-term work across research into brain tumours so that tumour behaviour, recurrence patterns and treatment response can be understood more clearly. In this tumour family, that kind of detail is what helps research move from broad labels towards more precise treatment progress.
Understanding different tumour types and supporting research
Clearer classification helps researchers study the right tumour, test the right treatment approaches and understand why progress may look different across the glioma family.
Brain tumours remain heavily underfunded, with just 1% of the national spend on cancer research allocated to them since records began in 2002. We are the only national charity focused on finding a cure for all types of brain tumours.
If you want to support that work, you can donate, fundraise, campaign or help raise awareness of the need for sustained investment in research into brain tumours.
About this explainer
This article summarises information published by Brain Tumour Research on glioma, tumour terminology and recent treatment developments, and presents it in a shorter explainer format for general readers.
Medical disclaimer
This information is for general awareness and educational purposes only. It does not constitute medical advice. If you are experiencing symptoms mentioned here, or have concerns about your health, contact your GP or a qualified medical professional for advice and assessment.
References used
Brain Tumour Research. Glioma | High and Low Grade | Brain Tumour Types. https://braintumourresearch.org/pages/types-of-brain-tumours-glioma
Brain Tumour Research. Breaking down brain tumour terminology. https://braintumourresearch.org/blogs/latest-news/blog-breaking-down-brain-tumour-terminology
Brain Tumour Research. First new adult brain tumour treatment in 20 years approved. https://braintumourresearch.org/blogs/latest-news/first-new-adult-brain-tumour-treatment-in-20-years-approved