What is a pituitary tumour?

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

The pituitary gland makes hormones. These control other hormone-producing glands in the body, such as the adrenal and thyroid glands. Hormones are chemical messengers that help control how organs and tissues in the body work.

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

  • the anterior (front)
  • posterior (back).

The anterior pituitary gland produces different hormones:

  • the growth hormone
  • prolactin, which causes the production of breast milk after childbirth
  • ACTH (adrenocorticotrophic hormone), which causes the production of hormones 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), which stimulates the ovaries in women
  • LH (luteinising hormone), which stimulates 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 when breastfeeding.

Pituitary gland tumours are a type of brain tumour. They are usually benign (not cancer). Benign tumours do not usually spread to other parts of the brain. But they may cause problems as they grow by pressing on surrounding tissue. They are usually called pituitary adenomas.

Pituitary gland tumours are either:

  • secreting (producing hormones)
  • non-secreting (not producing hormones).

Secreting tumours can release a large amount of pituitary hormones. They are named after the hormone that is being over produced. An example of this is a prolactin-secreting tumour.

Symptoms of a pituitary tumour

As a pituitary tumour grows, it can press on or grow into nearby areas of the brain. This can cause symptoms because it stops that part of the brain from working normally. Symptoms can be caused by direct pressure from the tumour itself. Or they can be caused by a change in your normal hormone levels. As the tumour grows, it can put pressure on the optic nerves. This can cause problems with eyesight.

Symptoms caused by a change in hormone levels often take a long time to develop.

Symptoms of secreting tumours relate to the hormones that are released.

Prolactin-secreting tumours

Prolactin-secreting tumours are the most common type of secreting tumour.

Symptoms for women with this type of tumour may include:

  • monthly periods (menstrual cycle) stopping or being irregular
  • not producing much breast milk.

Symptoms in men may include:

  • not being able to have an erection
  • reduced sex drive (libido).

We have more information about sexual difficulties in men.

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 in men and fertility in women.

Growth hormone-secreting tumours

Over-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 symptoms such as:

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

TSH (thyroid-stimulation hormone) - secreting tumours

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

  • weight loss
  • palpitations (a fast or irregular heart beat)
  • 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 facial hair in women
  • emotional changes such as depression.

It can also cause high blood pressure, 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). They cause an over-production of oestrogen in women and over-production of testosterone in men.

Posterior pituitary tumours

Posterior pituitary gland tumours are very rare. The most common symptom is a condition called diabetes insipidus. This is different from the more common type of diabetes called diabetes mellitus. The main symptoms of diabetes insipidus are:

  • being thirsty
  • large amounts of weak urine (pee).

Causes of a pituitary tumour

The causes of these tumours are not known, but research is being done to find out more. Rarely, there may be a genetic cause.

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 will examine your eyes to 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 gland tumours are often found during a blood test. If high or low 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.

We have more about how brain tumours are diagnosed.

The Pituitary Foundation also have information and support.

Getting support

Being diagnosed with a brain tumour can make you feel shocked, frightened, angry or upset. There is no right or wrong way to feel. Talking about your feelings can often help.

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

How diagnosis affects your right to drive

Most people diagnosed with a brain tumour will not be allowed to drive for a time after their diagnosis. Your doctor, surgeon or specialist nurse will tell you if this applies to you. 

If you have a driving licence, you must tell the licensing agency you have been diagnosed with a brain tumour.

You could be fined if you do not tell them. You could also be prosecuted if you have an accident.

Treatment for a pituitary tumour

The main treatments for pituitary gland tumours are surgery and radiotherapy. Drug treatments are also used for some pituitary tumours.

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

The team will include:

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

Your specialist doctor and nurse will explain the aims of your treatment 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.

Surgery

Surgery is the most common treatment for most pituitary tumours. Sometimes the whole pituitary gland may need to be removed.

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, up the nose through to the pituitary gland. Because this operation does not involve cutting into the skull, recovery is much quicker than other operations for brain tumours.

Rarely, an operation called a craniotomy might be needed.

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

Radiotherapy

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

Radiotherapy may be used:

  • after surgery, if the tumour cannot be completely removed
  • as the main treatment for a pituitary tumour.

A type of radiotherapy called stereotactic radiosurgery (SRT) can be used to treat some small tumours that are not close to the optic nerve. Radiosurgery is a type of stereotactic radiotherapy.

Other possible treatments

Some prolactin-secreting tumours can be treated with drugs 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 need to take medication to replace the hormones that are normally produced. This is called hormone replacement treatment.

Side effects of treatment for a pituitary tumour

Your specialist doctor or 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.

We have more information about coping:

Fertility

Your doctor or nurse can tell you if treatment is likely to affect your fertility. We have more information about fertility in women and men.

Clinical trials

Clinical trials are medical research trials involving people. Doctors may use clinical trials to test new treatments, find new drugs, or improve the way treatments are given.

Because 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.

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.

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.

Reviewed: 29 September 2016
Reviewed: 29/09/2016
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Next review: 28 February 2019
Next review: 28/02/2019