Medical language can sometimes feel confusing or overwhelming. This A–Z guide explains some of the terms you may hear during diagnosis, treatment and care for a brain tumour.
We hope this glossary helps patients, families and carers better understand the words used by healthcare professionals and feel more confident when navigating information about brain tumours.
A type of non-cancerous brain tumour which usually grows slowly and does not spread to other parts of the body. Also known as vestibular schwannoma.
A term used to describe several different types of tumour, meaning that at this stage the tumour is formed of cancer cells that are dividing rapidly and have little or no resemblance to normal cells.
A blood protein produced by the body’s immune system in response to and counteracting harmful substances, called antigens. The antigen identifies something such as a virus, bacteria or cancer cell as ‘not self’ and therefore potentially a threat. The antibody then either neutralises or destroys the cell that has been identified. Examples of antigens include bacteria, viruses and fungi.
A type of drug that is used to prevent or treat seizures or convulsions by controlling abnormal electrical activity within the brain.
An antigen is a foreign substance that is recognised by antibodies as being ‘non-self’ and therefore posing a potential threat to our health. This then stimulates an immune response. Antigens include toxins, chemicals, bacteria, viruses, or other substances that come from outside the body.
The death of cells occurs as a controlled part of an organism’s development. This is one method the body uses to get rid of unneeded or at the end of their natural life cycle or abnormal,
This is a coalition of UK research-funding charities. There are 140 member charities, which together spend over £1.4 billion a year on research in the UK. In order to join the AMRC, a charity has to demonstrate transparency by the use of peer review on all research applications, as well as publishing a research strategy. Research funded by an AMRC member attracts an additional 26% of its value to cover the cost of University overheads, and this is funded by the Charity Research Support Fund.
A common type of brain tumour in adults and children belongs to a group of brain tumours called gliomas. These tumours develop from a cell called astrocytes, which support the nerve cells in the brain.
This term is usually used to describe a low-grade tumour which grows slowly and is unlikely to invade the surrounding brain tissue. They are often referred to as non-cancerous.
A biopsy is a form of neurosurgery in which a hollow needle is inserted into the brain tumour to take small samples from various areas within that tumour. The samples are then sent for analysis to determine a precise diagnosis.
For full genetic profiling, freshly frozen tissue samples are crucial, although paraffin-embedded samples (the more traditional, less expensive way to preserve brain tissue) provide enough information to make a diagnosis that is detailed enough to guide the planning of treatment currently available on the NHS in the UK.
A membrane that surrounds the blood vessels within the brain to prevent the passage of toxic factors that may be present in the blood. The brain is very sensitive and needs to be protected from toxic factors, which may be present in the blood. Therefore, a specific membrane, the blood-brain barrier, surrounds the blood vessels within the brain to prevent toxic factors from entering the brain. However, it can also prevent certain drugs from entering the brain, and this is why some drugs, especially those that have been developed for other tumours, are ineffective for the treatment of brain tumours.
A type of internal radiotherapy where a small radioactive material/source is put into the body, close to the cancer. This delivers radiotherapy to that area, destroying cancer cells, while healthy tissue near that area gets a lot less radiation.
A brain cyst is a fluid-filled sac in the brain. They can be non-malignant or malignant. Even if a brain cyst isn’t cancer, it can still cause problems. Some brain cysts can be present from birth.
A term used to describe a range of symptoms, including poor concentration, trouble thinking or thinking more slowly, and confused or fuzzy thoughts.
There is one cannabis-based drug, Sativex, which is licensed to help the symptoms of multiple sclerosis. The active ingredients, which are derived from the cannabis plant, are called cannabinoids. These ingredients are also contained in cannabis oil, although usually at a much lower concentration. Some people have used cannabis oil as a potential treatment for their brain tumours, although there is no evidence that it is of benefit. Because cannabis oil is available to purchase without a prescription, primarily over the internet, it is not considered a medicinal product. Therefore, the quantity and nature of the cannabinoids present may vary, and there is no quality control process to monitor the contents.
The fluid that surrounds and protects the brain and spinal cord. It is made of tissue that lines the ventricles in the brain.
A slow-growing cancer is found inside the spine or the base of the skull.
A network of blood vessels in the ventricles of the brain, which are covered by a thin layer of cells. These make the cerebrospinal fluid.
The use of drugs to treat cancer is referred to as chemotherapy. These drugs act to halt the growth of the tumour cells or to kill them. While there are many different types of drugs available, the majority of these can’t be used for the treatment of brain tumours because they can’t cross the blood-brain barrier to get to the site of the tumour. The most common drug used for the treatment of brain tumours is temozolomide.
Is an advanced practice registered nurse. A CNS is trained in advanced physiology, pharmacology and physical assessment in addition to their particular areas of speciality.
Research studies which test a medical, surgical or behavioural intervention in people. These trials are a primary way for researchers to determine new forms of treatment or prevention.
A colloid cyst is a non-malignant growth that is filled with fluid and usually found in the central part of the brain, in or near the third ventricle.
A scan that uses a diagnostic imaging device, which in turn uses a combination of X-rays and computer technology, to produce images of the inside of the body.
A tumour which often occurs above the pituitary gland. This is located at the bottom of the brain. The gland is the size of a pea and controls many vital functions.
The surgical removal of part of the bone from the skull to expose the brain. The bone flap is temporarily removed and then replaced after the brain surgery is complete.
The surgical removal of as much of the tumour as possible. This may increase the chance of chemotherapy/radiation therapy to kill the tumour cells. Debulking may also be used to relieve symptoms or to prolong life.
A diffuse brain tumour is one that does not have a clear boundary, instead infiltrating healthy brain tissue and spreading between and around surrounding brain cells.
DNA stands for deoxyribonucleic acid. It contains the genetic information that provides the instructions for our body to make proteins with a huge range of different functions. It is the hereditary material in humans and almost all other organisms.
DCVax® are personalised immunotherapy treatment for solid tumour cancers developed by a company called Northwest Biotherapeutics. DCVax®-L is the name of the vaccine developed for treating glioblastoma (GBM), the most common and aggressive brain tumour in adults.
Swelling is caused by too much fluid trapped in the body’s tissues.
Tumours develop from cells that are left over from the early stages of development, while still developing in the mother’s womb. Also known as embryonic cells.
These develop from ependymal cells, which line the fluid-filled areas of the brain and spinal cord.
A symptom, not a condition. Often described as tiredness, but is different to just feeling tired or sleepy. It is a lingering tiredness that is constant and limiting.
A type of cancer that starts within the brain or spinal cord. It grows quickly and can invade healthy tissue. Often forms from cells called astrocytes, which support nerve cells.
A growth of cells that starts in the brain or spinal cord. The cells look very similar to glial cells, which are healthy brain cells that support the brain and spinal cord.
The tumour cells grow quickly and are likely to spread into nearby tissue, and the tumour cells look very different from normal cells.
The tumour grows and spreads very quickly. These tumours can be difficult to treat and may not be removable by surgery, depending on the size, location within the brain and the extent to which they have invaded the surrounding tissue.
This is the study of cells and tissues under a microscope. It involves the preparation of a thin slice of tumour tissue using a specialised cutting device and placing it on a glass microscope slide. This can then be examined to obtain specific information about a tumour, such as its type and grade.
Drugs that inhibit the activity of the immune system by suppressing the immune response of an individual, making it less effective.
A treatment that uses a person’s own immune system to fight cancer. It can boost or change how the immune system works to find and attack cancer cells.
Although tumours are different to normal cells and should be identified as ‘foreign’ by our immune system, they use specific mechanisms to prevent this from happening and essentially put the immune cells near the tumour into hibernation.
Immunotherapy refers to the reawakening of the immune system in order to allow it to attack the tumour cells. Two main approaches are used: one stimulates the cells into action, and these drugs are called checkpoint inhibitors. An example of this is the drug nivolumab, which has undergone clinical trials which were unsuccessful. However, other trials using similar drugs are in the planning stage. The second uses a vaccination approach. This involves the generation of a part of the surface of the tumour that can be injected into the body to produce antibodies that can attack the tumour cells.
A brain injury or health problem can cause growing pressure inside your skull.
A region within an organ or tissue that has suffered damage through injury or disease.
Soluble aspirin forms a suspension and appears as a cloudy solution rather than fully dissolving in water. Because it is not fully soluble, only a small amount will cross the blood-brain barrier to enter the brain. By combining aspirin with another compound, which itself has no action in the brain, researchers have developed a truly soluble form of the drug that is more likely to enter the brain. Initial studies using brain tumour cells grown in the lab suggest that this form of aspirin may kill the cells, and trials are currently being planned to see whether this effect can be seen in the brain itself.
Composed of cells that look more like normal cells and tend to grow and spread more slowly than high-grade cancer cells.
The tumour grows slowly and rarely spreads into nearby tissues. Depending on its location, it should be possible to remove the entire tumour by surgery.
The tumour grows slowly but may spread into nearby tissue, and the tumour may regrow at some stage following surgery. Some tumours may develop to form a higher-grade tumour.
A thin needle is inserted between the bones in the lower spine. This could be performed for several reasons, such as to take a sample of spinal fluid or to inject medicine.
Also known as primary central nervous system (CNS) lymphoma. A cancer that starts in the lymph glands or other organs in the lymphatic system.
Lysed tumour cells have had their cell membrane broken so that their contents have spilt out into the bloodstream, resulting in the death of the tumour cells.
A rare non-cancerous brain tumour which starts in the cells that line the blood vessels of the brain, spinal cord and brain stem. It usually grows and slows over some years.
A high-grade tumour (see H above)
Cancer cells tend to grow and spread more quickly than low-grade cancer cells.
The branch of biology that studies the microscopic anatomy of biological tissues.
A build-up of fluid in the brain can put pressure on the brain and damage it.
A non-invasive imaging technology that produces three-dimensional, detailed anatomical images. MRI scanners use strong magnetic fields and radio waves to generate these images of organs in the body.
These are high-grade tumours where the cells are growing rapidly and are actively spreading to neighbouring tissue.
A primary central nervous system (CNS) tumour. Begins in the brain or spinal cord. It is one of the most common types of primary brain tumour.
The spread of cancer cells where the cells break away from the original tumour and travel through the blood or lymph system to form a new tumour in other organs or tissues within the body.
Occurs when cancer cells begin in another part of the body and then spread to the brain through the bloodstream or lymphatic system.
A biological marker, also known as a genetic marker, is found in blood/body fluids/tissues and is a sign of normal or abnormal conditions or disease. The marker may be utilised to observe how well the body responds to treatment. Molecular markers are identified using biochemical analysis (genetic profiling) of a brain tumour sample removed during surgery (biopsy). They can then be used to diagnose the exact type of tumour and sometimes guide certain treatments that have been shown to benefit tumours that carry the same molecular marker.
Myelin is an insulating layer, or sheath, that forms around nerves, including those in the brain and spinal cord. It allows electrical impulses to transmit quickly and efficiently along the nerve cells. If myelin is damaged, these impulses slow down
Diagnoses, assesses and performs surgery on disorders affecting the brain or spinal cord.
A rare type of brain tumour that develops from glial cells called oligodendrocytes. They are mostly found in the frontal lobe of the cerebrum, but can also start in the spinal cord, though this is very rare.
A doctor who specialises in the prevention, diagnosis and treatment of cancer is called an oncologist. They may also be called a cancer specialist. Those who focus on the treatment of brain tumours are referred to as neuro-oncologists.
An ophthalmologist is a medically qualified doctor who has undergone specialist training in the diagnosis and treatment of eye conditions and is usually qualified as an eye surgeon. If an ophthalmologist discovers a brain tumour during an eye examination, they can provide a referral to a neurosurgeon.
An optometrist prescribes and fits glasses and contact lenses, and is trained to understand the mechanisms of the eye, including health conditions such as a brain tumour that may present itself with symptoms affecting sight. If an optometrist discovers symptoms that indicate a brain tumour, a GP can provide a referral to a neurologist or a neurosurgeon for further investigation.
This is a new type of therapy called ‘Tumour Treating Fields’. It involves placing electrodes onto a person’s shaved head, which are then kept in place by a skin-tight cap. These are connected to a battery, which is carried around for 18 hours per day. The electrodes create low-intensity, alternating electrical fields that are designed to slow the growth of cancer cells. While the results look promising, further research is required to understand who would benefit from the treatment. The high cost makes it unlikely to be available on the NHS in the near future.
About improving the quality of life of anyone facing a life-threatening condition. It can include physical, emotional and spiritual care. Read more about end-of-life and palliative care.
The study and understanding of how illnesses and diseases develop and work, and their impact on people. A clinical pathologist will use several different techniques, including histology, in order to make a diagnosis, and this will provide information on what treatment to use. A pathologist works in close collaboration with clinical staff, including oncologists.
This is the evaluation of scientific, academic or professional work by others working in the same field.
Short chains of amino acids become classed as proteins once they join together to form longer chains.
The peripheral nervous system connects the central nervous system, which lies inside the brain and spinal cord, to other organs. Peripheral nerves are 12 cranial nerves (that originate from the brain and brainstem), the nerves in the spine and the autonomic nerves. These nerves then form communication networks between the central nervous system (CNS) and the body parts.
These are primary central nervous system tumours which begin in the brain but can spread to the spinal cord.
An abnormal growth in the pituitary gland. Most are non-cancerous, benign pituitary gland tumours, also known as pituitary adenomas.
Tumours that originate from the tissues of the brain or its surroundings. They are categorised as glial or non-glial and non-malignant or malignant.
A new type of radiotherapy that uses a specific form of radiation called proton beams to treat specific types of cancer. It enables a dose of high-energy protons to be precisely targeted at a tumour, reducing the damage to surrounding healthy tissues and organs.
A treatment where radiation is used to kill cancer cells. It can be given in several ways, including with chemotherapy for some cancers, and is usually given in hospitals.
A process of assessment, treatment and management to achieve the maximum potential for physical, cognitive, social and psychological function for quality of living.
The surgical removal of part of an organ/structure, including part or all of a brain tumour
Ribonucleic acid is a nucleic acid present in all living cells. RNA’s main role is to act as a messenger, copying the instructions contained within the DNA of our cells, and then using those instructions to make proteins. However, in some viruses, RNA itself carries the genetic blueprint for the organism.
Caused by cancer cells spreading to the brain from a different part of the body.
A sudden, uncontrolled burst of electrical activity in the brain that causes changes in behaviour, movements, feelings and levels of consciousness.
Tumours that start in the spinal cord are rare. The most common types are meningiomas, tumours of the spinal nerves and ependymomas.
A fluid-filled space down the centre of the spinal cord.
Stereotactic radiotherapy gives radiotherapy from different angles around the body so that the beams meet the tumour and therefore give a higher dose of radiation to the tumour and a lower dose to the tissues around it.
Anti-inflammatory medicines are used to treat a range of conditions.
The act of performing a surgical procedure or operation.
Part of the immune system that focuses on specific foreign particles. T cells protect the body from infections (and cancer) by specifically recognising anything ‘non-self’, such as viruses and bacteria, and killing infected cells. T cells can also recognise and eliminate tumour cells because tumour cells make many mutated proteins, which are seen by T cells as ‘non-self’. Activation of an anti-tumour T-cell response is the ultimate goal of immunotherapy.
There are many different types of brain tumours. The type of tumour depends on its location within the brain, the cells from which it originated, the pathology and its genetic makeup. These factors also influence the shape and growth rate. Tumours can be classified as low-grade or high-grade.
Are a communicating network of spaces in the brain’s parenchyma, filled with cerebrospinal fluid.
Also known as acoustic neuromas. They are non-cancerous tumours that start in the nerve that connects the brain to the ear.
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