Pituitary gland tumours

What is a pituitary gland?

The pituitary gland is a small, oval-shaped gland at the base of the brain, behind the bridge of the nose. It is below the nerves that lead to and from the eyes. These are called the optic nerves.

The pituitary gland makes hormones. Hormones are chemical messengers that help control how organs and tissues in the body work.

Hormones produced by the pituitary gland control other glands that produce hormones in the body, such as the adrenal and thyroid glands.

The pituitary gland is divided into 2 parts which produce different hormones:

anterior (front)
posterior (back).

The anterior pituitary gland produces:

growth hormone
prolactin, which causes the production of breast milk after childbirth
ACTH (adrenocorticotrophic hormone), which causes the production of a steroid hormone called cortisol from the adrenal glands
TSH (thyroid-stimulating hormone), which causes the production of hormones from the thyroid gland to control growth, metabolism and reproduction
FSH (follicle-stimulating hormone) and LH (luteinising hormone), which stimulate the ovaries and testes to produce sex hormones.

The posterior pituitary produces:

ADH (anti-diuretic hormone), which controls the amount of water in the urine produced by the kidneys
oxytocin, which stimulates the contraction of the womb during childbirth and the release of breast milk when breastfeeding.

What is a pituitary tumour?

Pituitary gland tumours are a type of brain tumour. The most common type of pituitary gland tumour is a pituitary adenoma.

A pituitary adenoma tumour is usually benign (not cancer). A benign tumour does not usually spread to other parts of the brain or outside the brain. But it may cause problems as it grows by pressing on surrounding tissue and may affect how the pituitary gland produces hormones.

Pituitary gland tumours either:

produce hormones – called functioning or secreting tumours
do not produce hormones – called non-functioning or non-secreting.

A secreting tumour can release a large amount of pituitary hormones. It is named after the hormone that is being over-produced. An example of this is a prolactin-secreting tumour, which is also called a prolactinoma.

Symptoms of a pituitary tumour

The type of symptoms can depend on the size and type of tumour.

Symptoms may happen if a tumour presses on or grows into nearby areas of the brain. This can stop that part of the brain from working normally. Symptoms can be caused by direct pressure from the tumour itself. The tumour may also put pressure on the nerve or optic pathways to the eyes. This can cause problems with eyesight.

Symptoms can also be caused by a change in your normal hormone levels. Symptoms of secreting tumours, (functioning pituitary tumours), relate to the hormones that are released.

If symptoms are caused by a change in hormone levels, they can often develop slowly, over a long time.

Prolactin-secreting tumours

Prolactin-secreting tumour is the most common type of secreting tumour.

Symptoms for women and people assigned female at birth with this type of tumour may include:

monthly periods (menstrual cycle) stopping or being irregular
producing breast milk or discharge from the nipples.

Symptoms in men and people assigned male at birth may include:

not being able to have an erection
reduced sex drive (libido)
discharge from the nipples, although this is rare.

We have more information about sexual difficulties.

You may also not be able to get pregnant or make someone pregnant (infertile). Sometimes a tumour may be found during tests for infertility.

We also have information about fertility.

Growth hormone-secreting tumours

Over-production of growth hormones can cause a condition called acromegaly. In children, excess growth hormones will lead to an increase in height. In adults, once growth has stopped, the excess growth hormones lead to growth of soft tissues, causing enlargement of hands, feet and lower jaw. It can also lead to symptoms such as:

high blood pressure
diabetes
excess sweating
sleep apnoea syndrome (pauses in breathing during sleep)
headache
joint pain.

TSH (thyroid-stimulation hormone) - secreting tumours

TSH-secreting tumours are very rare. Symptoms may include:

weight loss
palpitations (a fast or irregular heartbeat)
feeling shaky
anxiety.

ACTH (adrenocorticotrophic hormone) - secreting tumours

Over-production of ACTH can produce symptoms that are the same as the symptoms of Cushing's syndrome. The main symptoms include:

a round face (called ‘moon face’)
weight gain
increased bruising
muscle wasting, causing difficulty climbing stairs or getting out of a chair
high blood pressure
increased facial hair in women and people assigned female at birth
emotional changes such as depression.

It can also cause diabetes and thinning of the bones (osteoporosis).

Other anterior pituitary tumours

These tumours are very rare. Tumours that secrete FSH (follicle-stimulating hormone) and LH (luteinising hormone) can cause an over-production of:

oestrogen, in women and people assigned female at birth
testosterone, in men and people assigned make at birth.

If an anterior pituitary tumour presses on the posterior pituitary gland, is can cause a condition called arginine vasopressin deficiency. This used to be called diabetes insipidus. The main symptoms of arginine vasopressin deficiency are:

being thirsty
passing large amounts of pale, watery urine (pee).

This is different from the more common type of diabetes called diabetes mellitus.

Causes of a pituitary tumour

The causes of pituitary tumours are not known, but research is being done to find out more. Rarely, there may be a genetic cause, particularly if they develop at a young age.

We have more information about risk factors and causes of brain tumours.

Tests and diagnosis for a pituitary tumour

Your doctors need to find out as much as possible about the type, position and size of the tumour so they can plan your treatment.

You may have the following tests:

Eye tests

Your doctor may do a test to check your visual fields (range of vision). This is to see if and how much the pituitary tumour might be affecting your vision.
Blood tests

The levels of most of the pituitary hormones can be tested in the blood.

This means some pituitary gland tumours are found following a blood test done for another health problem. Pituitary tumours can produce too much of a particular pituitary hormone, or reduce the normal production of pituitary hormones.
MRI scan

If high or low levels of pituitary hormones are found in your blood, your doctor may arrange for you to have an MRI scan. The scan can confirm whether there is a pituitary tumour. Many pituitary tumours are picked up on a brain scan that was done for another health problem.

We have more about how brain tumours are diagnosed.

Treatment for a pituitary tumour

The main treatments for a pituitary gland tumour are drug treatments, surgery and radiotherapy. Sometimes pituitary tumours that are not causing symptoms may be regularly monitored (active surveillance) instead of being treated straight away.

Your treatment will be planned by a team of specialists called a multidisciplinary team (MDT).

The team may include:

an endocrinologist – a doctor who specialises in disorders of hormone production
a neurosurgeon – a doctor who operates on the brain
a pathologist – a doctor who specialises in examining tissue samples collected during surgery
a radiologist – a doctor who specialises in x-rays and scans including brain scans
an oncologist – a doctor who specialises in treating brain tumours with radiotherapy or chemotherapy
a specialist nurse - a nurse who gives you information and support
other healthcare professionals, such as a physiotherapist or dietitian, or a doctor who specialises in disorders of the eyes (ophthalmologist).

Your specialist doctor and nurse will explain the aims of the treatment you have been offered and what it involves. They will talk to you about the benefits and disadvantages of different treatment types. They will also explain the risks and side effects.

You may be given a choice of treatment options. You will have time to talk about this with your hospital team before you make any treatment decisions.

You will need to give permission (consent) for the hospital staff to give you the treatment. Ask any questions about anything you do not understand or feel worried about. Tell your specialist if you need more information or more time to decide on a treatment.

Drug treatments (medication)

Prolactin-secreting tumours can be treated with drugs (medication). These include bromocriptine, cabergoline and quinagolide. They reduce the production of prolactin and the size of the tumour, and may also help control symptoms.

Surgery

Surgery may be used for some pituitary gland tumours. The aim is to remove all or as much of the tumour as it is safely possible.

The most common type of surgery used is called endoscopic transsphenoidal surgery (or resection). The surgeon passes a thin tube with a camera on the end, into the nose to reach the pituitary gland.

Sometimes, an operation called a craniotomy might be needed.

Your surgeon will explain what type of operation is best for you, and what to expect.

Prolactin-secreting tumours may be treated differently (see above). They are usually treated with medicines as they are more likely to respond to medication.

We have more information about surgery for brain tumours and about what to expect before and after surgery.

Radiotherapy

Radiotherapy uses high-energy x rays to destroy the tumour cells. Radiotherapy may be used for all types of pituitary tumour.

Radiotherapy may be used:

if the tumour has grown back after surgery (recurrence)
after surgery, if the tumour cannot be completely removed
to control hormone secretion, if levels are still high following surgery and treatment with medication
as the main treatment for a pituitary tumour, in rare situations.

Radiotherapy is usually given as a course of treatments, every weekday over a period of 5 or 6 weeks, depending on the type of tumour. Occasionally, a type of radiotherapy called stereotactic radiosurgery (SRS) can be used to treat some small tumours that are not close to the optic nerve. This is given as a single treatment.

Your doctor will explain about how radiotherapy is given and the possible side effects. You can ask them any questions you have.

We have more information about side effects of radiotherapy.

Active surveillance (active monitoring)

If a pituitary tumour is not causing symptoms and is found when having tests for another health problem, regular monitoring may be recommended instead of starting treatment straight away. This is because for some pituitary tumours the side effects of treatment may outweigh the benefits.

You have regular monitoring with scans, blood and eyesight tests. This is also called active monitoring. You may have treatment if there are signs that the tumour is growing or starts to cause symptoms. After treatment you continue to be monitored.

Side effects of treatment for a pituitary tumour

Your doctor or specialist nurse will explain your treatment and possible side effects. Most side effects are short term and will improve gradually when the treatment is over. Some treatments can cause side effects that do not get better. These are called long-term effects. You may also get side effects that start months or years later. These are called late effects.

Side effects of treatment for a pituitary tumour will depend on the type of pituitary tumour and the treatment used. Some side effects may include:

Effects on hormones

Pituitary gland tumours, and treatments for them, can affect hormone levels in the body. After your treatment has finished, you will have regular check-ups at a clinic that specialises in hormone imbalances, called an endocrinology clinic. You will have regular blood tests to check your hormone levels. These may continue for several years.

Hormone replacement therapy

If the normal pituitary function is affected by the tumour, surgery or radiotherapy, you may need to take medication to replace the hormones that are normally produced. This is called hormone replacement treatment. You usually need to take the hormone replacement for the rest your life. You will have regular appointments with a team that specialises in hormones, called an endocrine team.

Eyesight problems

Pituitary gland tumours and treatments for them can affect your eyesight. You may have further scans and eye tests. You may also need to regularly see an ophthalmologist, a doctor who specialises in disorders of the eyes.

Fertility

Your doctor or nurse can tell you if treatment is likely to affect your fertility (being able to get pregnant or make someone pregnant). We have more information about fertility.

We have more information about side effects of radiotherapy and surgery for brain tumours.

Clinical trials

Clinical trials are a type of medical research involving people. They are important because they show which treatments are most effective and safe. This helps healthcare teams plan the best treatment for the people they care for.

Trials may test how effective a new treatment is compared to the current treatment used. Or they may get information about the safety and side effects of treatments.

They will give you information about the clinical trial so that you understand what it means to take part. If you decide not to take part in a trial, your specialist doctor and nurse will respect your decision. You do not have to give a reason for not taking part. Your decision will not change your care. Your doctor will give you the standard treatment for the type of tumour you have.

Clinical trials also research other areas. These include diagnosis and managing side effects or symptoms. As these tumours are rare, there may not always be a relevant clinical trial happening. If there is, your doctor or nurse may ask you to think about taking part.

We have more information about clinical trials.

After treatment for a pituitary tumour

Treatment of pituitary tumours is usually very successful, although many people will have to take hormone replacements, sometimes for the rest of their lives. After your treatment has finished, you will probably have regular check-ups at an endocrinology clinic. These may continue for several years. You will have blood tests to monitor your hormone levels. You may also have further scans and eye tests.

Many people find they get very anxious before appointments. This is natural. It can help to get support from family, friends or a specialist nurse.

How a brain tumour may affect your right to drive

Some people with a pituitary tumour may not be allowed to drive for a period of time after treatment. This will depend on whether the tumour is affecting your eyesight and the type of surgery or other treatment you had. Your doctor, surgeon or specialist nurse can advise if this applies to you.

If you have a driving licence, you must tell the licencing agency (DVLA or DVA) that you have been diagnosed with a brain tumour. You might have to surrender (give up) your license for a period of time. Your doctor or clinical nurse specialist can discuss how this might apply in your individual situation.

If you send back your license it can make it easier to reapply for a new license. You can reapply for your license if you meet the required criteria to drive again in the future (see below).

You can find out more information on the following websites. If you live in England, Scotland or Wales contact the Drivers and Vehicle Licensing Agency (DVLA). If you live in Northern Ireland, contact the Driver and Vehicle Agency (DVA).

You can be fined if you do not tell the DVLA or DVA about a medical condition that affects your driving. If you continue to drive when you have been advised not to, you will not be covered by your insurance, and you could be prosecuted if you have an accident.

Reapplying for your licence

If you have surrendered your licence, you may be able to apply to get your licence back after a period of time. This will depend on whether you meet the required criteria.

These include:

how long it is since any treatment
your most recent brain scan results
your current symptoms
your eyesight.

You can contact the DVLA or DVA and submit forms to reapply. They may ask your doctor for medical information about you.

Your doctor or clinical nurse specialist can tell you more about this.

Getting support

Being diagnosed with a brain tumour may cause a range of different emotions. There is no right or wrong way to feel. It may help to get support from family, friends or a support organisation.

Macmillan is also here to support you. If you would like to talk, you can:

Call the Macmillan Support Line for free on 0808 808 00 00
Chat to our specialists online
Visit our pituitary tumour forum and our brain cancer forum to talk with people who have been affected by pituitary tumours, share your experience, and ask an expert your questions.

You may also want to get support from a brain tumour charity, such as:

References

Below is a sample of the sources used in our pituitary gland tumours information. If you would like more information about the sources we use, please contact us at informationproductionteam@macmillan.org.uk

Pituitary Adenoma. Sophia Russ et al. Last Update: March 2023. Available from: www.ncbi.nlm.nih.gov/books/NBK554451/ [accessed June 2024]

Diagnosis and management of prolactinomas and non-functioning pituitary adenomas. BMJ 2014; Available from: www.bmj.com/content/349/bmj.g5390 [accessed June 2024]

National Institute for Health and Care Excellence (NICE) Brain tumours (primary) and brain metastases in over 16s. Quality standard [QS203] Published: 07 December 2021. Neurological rehabilitation. Available from: www.nice.org.uk/guidance/qs203/chapter/quality-statement-5-neurological-rehabilitation#quality-statement-5-neurological-rehabilitation [accessed June 2024]

Cancer Information Development team

Author

Professor Catherine McBain

Reviewer

Consultant Clinical Oncologist

Date reviewed

Reviewed: 01 May 2024

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Next review: 01 May 2027

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