Pituitary Tumours

Pituitary tumours are tumours found in the pituitary gland, a small organ about the size of a pea in the centre of the brain just above the back of the nose. The pituitary gland makes hormones that affect the growth and the functions of other glands in the body.

Most pituitary tumours are benign. They grow very slowly and do not spread to other parts of the body.

If a pituitary tumour is found, the pituitary gland may be making too many hormones. This can cause other problems in the body. Tumours that make hormones are called functioning tumours, while those that do not make hormones are called non-functioning tumours.

Certain pituitary tumours can cause a disease called Cushing’s disease, in which too many hormones called glucocorticoids are released into the bloodstream. This causes fat to build up in the face, back, and chest, and the arms and legs to become very thin. Other symptoms include too much sugar in the blood, weak muscles and bones, a flushed face, and high blood pressure. Other pituitary tumours can cause a condition called acromegaly. Acromegaly means that the hands, feet, and face are larger than normal and in very young people, the whole body may grow much larger than normal. Another type of pituitary tumour can cause the breasts to make milk, even though a woman may not be pregnant, periods may stop as well.

A doctor should be seen if there are symptoms such as:

  • Headaches.
  • Trouble seeing.
  • Nausea or vomiting.
  • Any of the symptoms caused by too many hormones.

If there are symptoms, a doctor may order laboratory tests to see what the hormone levels are in the blood. The doctor may also order an MRI (magnetic resonance imaging) scan, which uses magnetic waves to make a picture of the inside of the brain. Other special x-rays may also be done.

The prognosis (chance of recovery) and choice of treatment depend on the type of tumour, and the patient’s age and general state of health.

 

Types of pituitary tumours

Once a pituitary tumour is found, more tests will be done to find out how far the tumour has spread and whether or not it makes hormones. A doctor needs to know the type of tumour to plan treatment. The following types of pituitary tumours are found:

ACTH-producing tumours

These tumours make a hormone called adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to make glucocorticoids. When the body makes too much ACTH, it causes Cushing’s disease.

Prolactin-producing tumours

These tumours make prolactin, a hormone that stimulates a woman’s breasts to make milk during and after pregnancy. Prolactin-secreting tumours can cause the breasts to make milk and menstrual periods to stop when a woman is not pregnant. In men, prolactin-producing tumours can cause impotence.

Growth hormone-producing tumours

These tumours make growth hormone, which can cause acromegaly or gigantism when too much is made.

Non-functioning pituitary tumours

Non-functioning tumours do not produce hormones.

How pituitary tumours are treated

There are treatments for all patients with pituitary tumours. Three kinds of treatment are used:

  • Surgery
  • Radiation therapy (using high-dose x-rays to kill tumour cells).
  • Drug therapy.

Surgery is a common treatment of pituitary tumours. A doctor may remove the tumour using one of the following operations:

  • A transsphenoidal hypophysectomy removes the tumour through a cut in the nasal passage.
  • A craniotomy removes the tumour through a cut in the front of the skull.

Radiation therapy uses high-energy x-rays to kill cancer cells and shrink tumours. Radiation for pituitary tumours usually comes from a machine outside the body (external radiation therapy). Radiation therapy may be used alone or in addition to surgery or drug therapy.

Certain drugs can also block the pituitary gland from making too many hormones.

ACTH-Producing Pituitary Tumours

Treatment may be one of the following:

  1. Surgery to remove the tumour (transsphenoidal hypophysectomy or craniotomy
  2. Radiation therapy. Clinical trials may be testing new types of radiation therapy.
  3. Surgery plus radiation therapy.
  4. Radiation therapy plus drug therapy to stop the tumour from making ACTH.

Prolactin-Producing Pituitary Tumours

Treatment may be one of the following:

  1. Surgery to remove the tumour (transsphenoidal hypophysectomy or craniotomy).
  2. Radiation therapy.
  3. Surgery, radiation therapy, and drug therapy.
  4. Drug therapy to stop the tumour from making prolactin. Clinical trials are testing new drugs for this purpose.

Growth Hormone-Producing Pituitary Tumours

Treatment may be one of the following:

  1. Surgery to remove the tumour (transsphenoidal hypophysectomy or craniotomy).
  2. Radiation therapy.
  3. Drug therapy to stop the tumour from making growth hormone.

Non-functioning Pituitary Tumours

Treatment may be one of the following:

  1. Surgery to remove the tumour (transsphenoidal hypophysectomy or craniotomy).
  2. Radiation therapy alone or in addition to surgery.

Recurrent Pituitary Tumours

Treatment of recurrent pituitary tumour depends on the type of tumour, the type of treatment the patient has already had, and other factors such as the patient’s general condition. Patients may want to take part in a clinical trial of new treatments.

BACK