Pituitary gland tumours
Although pituitary tumours are classified as brain tumours, they have very few similarities to other types of brain tumour. Much of our general information about brain tumours will not be appropriate for people with pituitary tumours, although you may still wish to
We hope this information answers your questions. If you have any further questions, you can ask your doctor or nurse at the hospital where you are having treatment.
The pituitary gland is a small, oval-shaped gland found at the base of the brain (see diagram below), below the optic nerve (the nerve that leads to and from the eye).
The pituitary gland produces hormones, which control and regulate the other glands in the body. These glands release hormones that help control and regulate growth and how the body works.
The pituitary gland is divided into two parts: the anterior (front) and posterior (back).
The anterior pituitary produces six hormones:
growth hormone, which controls growth
prolactin, which stimulates the production of breast milk after childbirth
ACTH (adrenocorticotrophic hormone), which stimulates the production of hormones from the adrenal glands
TSH (thyroid-stimulating hormone), which stimulates the production of hormones from the thyroid gland
FSH (follicle-stimulating hormone) and LH (leuteinising hormone), which stimulate the ovaries in women and the testes in men.
The posterior pituitary produces:
ADH (anti-diuretic hormone), which reduces the amount of urine produced by the kidneys
oxytocin, which stimulates the contraction of the womb during childbirth and the release of breast milk for breastfeeding.
Cells within the brain normally grow in an orderly and controlled way. But if for some reason this order is disrupted, the cells continue to divide and form a lump or tumour.
A tumour can be either benign or malignant. Although a benign tumour can continue to grow, the cells do not spread from the original site. In a malignant tumour, the cells can invade and destroy surrounding tissue and may spread to other parts of the brain.
Almost all tumours of the pituitary gland are benign and do not spread. They are sometimes called adenomas.
Pituitary tumours are either secreting (producing hormones) or non-secreting tumours (not producing hormones). Secreting tumours can release excess amounts of any of the pituitary hormones, and are named after the hormone that’s being overproduced, for example a prolactin-secreting tumour.
About 4,700 people are diagnosed with brain tumours each year in the UK. About 1 in 10 (10%) of these tumours are in the pituitary gland. They are most commonly found in young or middle-aged adults.
Causes of a pituitary tumour
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As with most brain tumours, the cause of pituitary tumours is unknown. Research is being carried out into possible causes.
Signs and symptoms of a pituitary tumour
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Signs and symptoms of pituitary tumours are caused either by direct pressure from the tumour itself or by a change in the normal hormone levels. As the tumour grows, it puts pressure on the optic nerve (which leads to the eye) and this often causes headaches and sight problems.
Symptoms caused by a change in hormone levels usually take a long time to develop.
These are the most common type of secreting tumour. Women with this type of tumour may notice that their monthly periods stop and they may also produce small amounts of breast milk. Symptoms in men may include impotence (loss of the ability to have an erection).
Infertility (inability to have children) is common in both men and women, and the tumour may be discovered during routine tests for infertility.
Symptoms of other secreting tumours will relate to the hormones that are released.
Growth hormone-secreting tumours
Excess production of growth hormones can cause a condition called giantism. This leads to abnormal growth, which is known as acromegaly. This causes enlargement of the hands, feet, lower jaw and brows, and can also lead to high blood pressure and diabetes.
A tumour that releases too much TSH may cause symptoms like weight loss, palpitations and feeling shaky and anxious. These tumours are extremely rare.
Overproduction of ACTH can produce a number of symptoms including Cushing’s syndrome, which is characterised by a round face (known as moon face), weight gain, increased facial hair in women and mental changes such as depression.
Other anterior pituitary tumours
Tumours that secrete FSH or LH are very rare and are likely to cause infertility.
Posterior pituitary tumours
Tumours in the posterior pituitary are very rare and disturbances in this area are more likely to be caused by pressure being applied to the area from the surrounding tissues.
The most common symptom of a problem in the posterior pituitary is a condition called diabetes insipidus, which is different from the more common diabetes mellitus. The main symptom of diabetes insipidus is being very thirsty and passing large amounts of very weak urine.
Tests and investigations for pituitary tumours
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For your doctors to plan your treatment, they need to find out as much as possible about the type, position and size of the tumour, so you may have a number of tests and investigations.
By examining your eyes, your doctor can detect pressure on the optic nerve, which may indicate that a tumour is present. A simple test may also be done to check your visual fields (range of vision).
Pituitary tumours are often discovered during a blood test. If high levels of pituitary hormones are found in your blood, your doctor may arrange for you to have a CT scan or MRI scan. The scans will normally be able to confirm whether a pituitary tumour is present or not.
CT (computerised tomography) scan
A CT scan takes a series of x-rays that build up a three-dimensional picture of the inside of the body. The scan is painless and takes 10-30 minutes. CT scans use small amounts of radiation, which will be very unlikely to harm you or anyone you come into contact with.
You will be given an injection of a dye, which allows particular areas to be seen more clearly. This may make you feel hot all over for a few minutes. If you are allergic to iodine or have asthma you could have a more serious reaction to the injection, so it’s important to let your doctor know beforehand.
MRI (magnetic resonance imaging) scan
This test is similar to a CT scan but uses magnetism instead of x-rays to build up a detailed picture of areas of your body. Before the scan you may be asked to complete and sign a checklist. This is to make sure it’s safe for you to have an MRI scan.
Before having the scan, you’ll be asked to remove any metal belongings including jewellery. Some people are given an injection of dye into a vein in the arm.
This is called a contrast medium and can help the images from the scan show up more clearly. During the test you will be asked to lie very still on a couch inside a long cylinder (tube) for about 30 minutes. It is painless but can be slightly uncomfortable, and some people feel a bit claustrophobic during the scan.
It’s also noisy but you’ll be given earplugs or headphones.
Treatment for a pituitary tumour
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Your treatment will usually be planned by a team of specialists known as a multidisciplinary team (MDT).
The team will usually include:
a doctor who specialises in disorders of hormone production (endocrinologist)
a doctor who operates on the brain (neurosurgeon)
a doctor who specialises in treating illnesses of the brain (neurologist)
a doctor who specialises in treating brain tumours (an oncologist)
a specialist nurse and possibly other healthcare professionals, such as a physiotherapist or dietitian.
Before you have any treatment, your doctor will give you full information about its aims and what it involves. They will ask you to sign a form saying that you give your permission (consent) for the hospital staff to give you the treatment. No medical treatment can be given without your consent.
Benefits and disadvantages of treatment
Treatment can be given for different reasons and the potential benefits will vary for each person. If you have been offered treatment that aims to cure your tumour, deciding whether to have the treatment may not be difficult. However, if a cure is not possible and the treatment is to control the tumour for a period of time, it may be more difficult to decide whether to go ahead.
If you feel that you can’t make a decision about the treatment when it is first explained to you, you can always ask for more time to decide.
You are free to choose not to have the treatment and the staff can explain what may happen if you do not have it. You don’t have to give a reason for not wanting to have treatment, but it can be helpful to let the staff know your concerns so they can give you the best advice.
Surgery is the most common treatment for most pituitary tumours. The aim of surgery is to remove the tumour and to leave at least some of the normal pituitary gland behind. This is not always possible, and in some cases the whole gland may need to be removed.
Surgery is usually carried out by making a small cut on the inside of the roof of the nose, or by making a small opening under the upper lip, to be able to reach the pituitary gland. This makes recovery after surgery much quicker than other operations for brain tumours.
Your doctor will explain the operation to you in more detail beforehand.
Some prolactin-secreting tumours can be treated with a drug treatment that reduces the production of prolactin. These drugs include bromocriptin and cabergoline.
If the whole pituitary gland is removed, drugs will have to be taken to replace the hormones that are normally produced (hormone replacement).
Radiotherapy treatment uses high-energy rays to destroy abnormal cells, and is an extremely effective and safe form of treatment. It's often used following surgery for all types of pituitary tumour.
Treatment of pituitary tumours is usually very successful, although many people will have to continue taking hormone replacements, sometimes for the rest of their lives. Regular check-ups at an endocrinology clinic are likely and may continue for several years. You may have further scans performed and will have blood tests to monitor your hormone levels.
You may find the idea of a tumour affecting your brain extremely frightening. The brain controls the body and not being in control is something that can be very worrying.
You may experience many different emotions, including anxiety and fear. These are all normal reactions and are part of the process many people go through in trying to come to terms with their condition.
Many people find it helpful to talk things over with their doctor or nurse, or with one of our cancer support specialists. Family members and close friends can also offer support.
The Pituitary Foundation
The Pituitary Foundation is a national organisation that provides information and support for people with pituitary disorders, and their relatives, friends and carers.
This information has been compiled using information from a number of reliable sources, including:
De Vita, et al. Cancer: Principles & Practice of Oncology. 8th edition. 2008. Lippincott Williams and Wilkins.
Greenman Y, Stern N. Non-functioning pituitary adenomas. Best Practice & Research Clinical Endocrinology & Metabolism. 2009. 23: 625–638.
Souhami, Tobias. Cancer and its management. 4th edition. 2003. Oxford Blackwell Scientific Publications.
Tonn, et al. Neuro-oncology of CNS tumours. 2006. Springer.
With thanks to Dr Catherine McBain, Consultant Clinical Oncologist, and the people affected by cancer who reviewed this edition. Reviewing information is just one of the ways you could help when you join our Cancer Voices network.