Pituitary gland tumours

Pituitary tumours start in the pituitary gland which produces and helps regulate hormones. Pituitary tumours, sometimes called adenomas, are usually always benign.

Symptoms can be caused by a tumour producing extra hormones, or by not producing enough hormones. Other symptoms, such as headaches or vision problems can be caused by the tumours pressing on the optic (eye) nerve.

You will need different tests, such as eye tests, blood tests, a CT scan or a MRI scan.

Your specialist will talk to you about the best treatment for you and explain the benefits and disadvantages. Surgery is the most common treatment. The operation is done through the nose without having to open the skull. Radiotherapy is often used after surgery. Some people with very small tumours may have a specialised type of targeted radiotherapy called stereotactic radiosurgery.

Doctors sometimes treat tumours that produce a hormone called prolactin with drugs that reduce prolactin levels.

If the whole pituitary gland is removed, you need to take drugs to replace the hormones that are normally produced (hormone replacement).

The pituitary gland

Pituitary tumours are classed as brain tumours. However they are different to most other brain tumours and are usually benign (non-cancerous).

This information should be read with our general information about brain tumours.

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 pided 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.

Brain cross-section labelled
Brain cross-section labelled

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Pituitary tumours

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 (non-cancerous) or malignant (cancerous). 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 non-cancerous 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.


As with most brain tumours, the cause of pituitary tumours is unknown. Research is being carried out into possible causes

Signs and symptoms

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.

Prolactin-secreting tumours

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 (inability 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 acromegaly. This leads to abnormal growth and causes enlargement of the hands, feet, lower jaw and brows. It can also lead to high blood pressure, diabetes and excess sweating. 

TSH-secreting tumours

A tumour that releases too much TSH may cause symptoms like weight loss, palpitations and feeling shaky and anxious. These tumours are extremely rare.

ACTH-secreting tumours

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 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.

Eye tests

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 scan

A CT (computerised tomography) scan uses x-rays to build a three-dimensional picture of the inside of the body. You may be given either a drink or injection of dye. This is to make certain areas of the body show up more clearly. This scan takes around 30 minutes and is painless. We have more detailed information about having a CT scan.

MRI scan

This scan uses magnetism to build up a detailed picture of areas of your body. You may be given an injection of dye, into a vein, to improve the images from the scan. This test is painless and will take around 30 minutes. We have more detailed information about having an MRI scan.


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.

The procedure is called endoscopic transphenoidal resection and involves the surgeon passing a thin tube up the nose to reach the pituitary gland. There is a camera at the end of the tube so the surgeon can see the area that needs to be removed. Because there is no need to open the skull to carry out the operation, recovery after surgery is much quicker than other operations for brain tumours.

Your doctor will explain the operation to you in more detail beforehand.

Drug treatment

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.

Some small tumours which are away from the optic nerves may be suitable for radiosurgery. Radiosurgery is a type of stereotactic radiotherapy. It aims radiotherapy beams directly at the brain tumour from different angles around your head. Radiosurgery is usually given in a single dose, but you may have more if necessary.


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.