What is a brain or spinal cord tumour?
A brain tumour starts in the cells of the brain. A spinal cord tumour starts in the cells of the spinal cord. Cells in the brain or spinal cord sometimes change and no longer grow or behave normally. These changes may lead to non-cancerous, or benign, conditions such as brain or spinal cord cysts. Cells in the brain and spinal cord can also change and form tumours. All brain and spinal cord tumours can cause severe or life-threatening symptoms.
Together, the brain and spinal cord form the central nervous system (CNS). The brain is the control centre of your body. It is a soft mass of nerve tissue protected by a bony covering called the skull. The spinal cord runs through the spine. It contains nerves that send information between the brain and the rest of the body.
Describing brain and spinal cord tumours
Brain and spinal cord tumours are classified based on their grade. The grade of a tumour tells you how quickly it is growing and how likely it is to spread.
- Low-grade, or benign, tumours grow slowly. They don’t usually grow into surrounding tissues or spread to other areas of the brain. Some low-grade tumours may develop into high-grade tumours.
- High-grade, or malignant, tumours grow quickly. They can grow into nearby tissues and spread to other parts of the brain or spinal cord. Malignant tumours that start in the brain and spinal cord rarely spread outside the CNS.
Types of brain and spinal cord tumours
Most often, brain and spinal cord tumours start in glial cells. These cells cover and support the nerve cells. A tumour that starts in glial cells is called a glioma. There are many different types of gliomas, including astrocytoma, oligodendroglioma, ependymoma and mixed gliomas. Gliomas are usually high grade, but some may be low grade.
Often, brain and spinal cord tumours start in the cells of the meninges. The meninges are the membranes that cover the brain and spinal cord. These tumours are called meningiomas. Most meningiomas are low grade, or benign. Others are high grade, or malignant.
Many other types of brain and spinal cord tumours develop in adults, but they are less common. These include craniopharyngioma, hemangioblastoma, glomus jugulare tumour and schwannoma. A rare form of non-Hodgkin lymphoma can also develop in the CNS. It is called primary central nervous system lymphoma (PCNSL).
When a tumour starts in brain cells, it is called a primary brain tumour. Other types of cancer can spread to the brain, but this is not the same disease as primary brain cancer. Cancer that starts in another part of the body and spreads to the brain is called brain metastasis or a secondary tumour. It is not treated in the same way as primary brain cancer. Find out more about brain metastasis.