Brain tumours in adults
In a brain tumour, cells grow abnormally, but this doesn’t mean a tumour is cancerous.
There are around 5,000 new cases of malignant brain tumours in the UK each year, often from cancers originating elsewhere in the body.
Although brain tumours in adults can be caused by cancer, benign tumours are possible. These may be due to medical conditions or may have no obvious cause.
Primary brain tumours emerge from the various cells that make up the brain and central nervous system and are named based on the kind of cell they first form in. The most common types of adult brain tumours are gliomas, the commonest type of which is called an astrocytoma. These tumours form from cells called astrocytes, which are cells that help support the nerve cells.
The second most common types of adult brain tumours are meningiomas. These form in the meninges, the thin layer of tissue that lines the brain and spinal cord and can grow from a number of different kinds of brain and spinal cord cells.
What's the difference between benign and malignant brain tumours?
Benign brain tumours are non-cancerous. Malignant primary brain tumours are cancers that originate in the brain. They typically grow faster than benign tumours and aggressively invade surrounding tissue. Although brain cancer rarely spreads to other organs, it will spread to other parts of the brain and central nervous system.
Benign brain tumours usually have clearly defined borders and are not usually deeply rooted in brain tissue. This makes them easier to surgically remove, assuming they are in an area of the brain that can be safely operated on. However, even after they've been removed they can still come back, though benign tumours are less likely than malignant ones to recur.
Although benign tumours in other parts of the body can cause problems, they are not generally considered to be a major health problem or to be life threatening. However, even a benign brain tumour can be a serious health problem. Brain tumours damage the cells around them by causing inflammation and putting increased pressure on the tissue under and around it as well as inside the skull.