Pituitary gland tumours

Pituitary tumours start in the pituitary gland, which produces and helps regulate hormones. Pituitary tumours, sometimes called adenomas, are usually benign (non-cancerous).

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

To diagnose a pituitary tumour, you will need different tests. These include blood tests, eye tests, and a CT scan or MRI scan.

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

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

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

The pituitary gland

Pituitary tumours are classed as brain tumours. But 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 at the base of the brain (see diagram below). It’s below the optic nerve (the nerve that leads to and from the eyes).

The pituitary gland produces hormones, which control and regulate many of 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 gland produces several different 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 that help control growth, metabolism, and reproduction
  • FSH (follicle-stimulating hormone), which stimulate the ovaries in women
  • LH (leuteinising hormone), which stimulate 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 in 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 or body.

Almost all tumours of the pituitary gland are non-cancerous and do not spread to other parts of the body. They are sometimes called pituitary adenomas.

Pituitary tumours are either secreting (producing hormones) or non-secreting (not producing hormones). Secreting tumours can release a large amount of any of the pituitary hormones, and are named after the hormone that is being over-produced. An example of this is a prolactin-secreting tumour.


Causes of pituitary tumours

As with most brain tumours, the cause of pituitary tumours is unknown. Research is being done into possible causes. Rarely, there may be a genetic cause.


Signs and symptoms of pituitary tumours

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 can put pressure on the optic nerve (which leads to the eyes) and this can cause sight problems.

Symptoms caused by a change in hormone levels often 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. They may also produce small amounts of breast milk . Symptoms in men may include impotence (inability to have an erection) and a reduced libido (sex drive). We have more information about sexual difficulties in men.

Infertility (inability to have children) is common in both men and women, and the tumour may be discovered during routine tests for infertility. We have more information about fertility in women and fertility in men.

Symptoms of other secreting tumours 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
  • excess sweating
  • sleep apnoea syndrome (pauses in breathing during sleep).

TSH-secreting tumours

A tumour that releases too much TSH may cause symptoms such as:

  • weight loss
  • palpitations (a fast or irregular heart beat)
  • feeling shaky and anxiety.

These tumours are extremely rare.

ACTH-secreting tumours

Over-production of ACTH can produce a number of symptoms of Cushing’s syndrome. The main symptoms are:

  • a round face (called ‘moon face’)
  • weight gain
  • increased facial hair in women
  • mental changes such as depression.

It can also lead to high blood pressure, diabetes and osteoporosis (bone thinning).

Other anterior pituitary tumours

Tumours that secrete FSH or LH cause over-production of oestrogen in women or testosterone in men. These tumours are very rare.

Posterior pituitary tumours

Tumours in the posterior pituitary are very rare. 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. This is different from the more common diabetes mellitus. The main symptoms of diabetes insipidus are being thirsty and passing large amounts of weak urine.


Tests and investigations for pituitary tumours

For your doctors to plan your treatment, they need to find out as much as possible about the tumour. You may have a number of tests and investigations to find out the type, position and size of the tumour.

Eye tests

By examining your eyes, your doctor can look for pressure on the optic nerve. This may mean there is a tumour. They may also do a simple test to check your visual fields (range of vision).

Blood tests

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 an MRI scan or CT scan. The scan can confirm whether there is a pituitary tumour or not.

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 about 30 minutes. We have more detailed information about having an MRI scan.

CT scan

A CT (computerised tomography) scan uses x-rays to build a three-dimensional (3D) 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 about 30 minutes and is painless. We have more detailed information about having a CT scan.


Treatment for pituitary tumours

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

The team will include:

  • a doctor who specialises in disorders of hormone production (endocrinologist)
  • a doctor who operates on the brain (neurosurgeon)
  • a doctor who specialises in disorders of the eyes (ophthalmologist)
  • a doctor who specialises in examining tissue samples collected during surgery (pathologist)
  • a doctor who specialises in treating brain tumours with radiotherapy or chemotherapy (oncologist)
  • a specialist nurse
  • other healthcare professionals, such as a physiotherapist or dietitian.

Consent

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 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 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 do not 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

Surgery is the most common treatment for most pituitary tumours. The aim of surgery is to remove the tumour and to leave as much as possible of the normal pituitary gland behind. This is not always possible, and in some cases the whole pituitary gland may need to be removed.

The procedure is called endoscopic transphenoidal surgery (or resection). It 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 do 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 that reduces the production of prolactin. These drugs include bromocriptine, cabergoline and quinagolide.

If part or all of the pituitary gland is removed, or stops working, you will have to take medications to replace the hormones that are normally produced (hormone replacement).

Radiotherapy

Radiotherapy treatment uses high-energy rays to destroy abnormal cells. It is an extremely effective and safe form of treatment. It is often used after surgery for all types of pituitary tumour. Radiotherapy beams are targeted directly at the brain tumour from different angles around your head. For pituitary tumours, radiotherapy may be recommended after surgery if the neurosurgeon could not safely remove the whole tumour during surgery.

Sometimes radiotherapy can be recommended as the main treatment for a pituitary tumour. Some small tumours that are away from the optic nerve 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.


Follow-up for pituitary tumours

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. You will probably have regular check-ups at an endocrinology clinic. These may continue for several years. You may have further scans, and you’ll have blood tests to monitor your hormone levels.


Useful organisations

The Pituitary Foundation is a national organisation that provides information and sup-port for people with pituitary disorders, and their relatives, carers and friends.