Pituitary Macroadenoma

What is the pituitary gland?

The pituitary is a small, pea-sized, oval-shaped gland that hangs from the hypothalamus, a structure at the base of the brain, by a thread-like stalk that contains blood vessels and nerves.

The pituitary gland controls a system of hormones in the body. Hormones regulate growth, the metabolism, the stress response and functions of the sex organs.

The pituitary gland produces many different hormones. Click here to read a great fact sheet.

What is a pituitary tumour?

A pituitary tumour or adonema (micro = less than 1cm diameter / macro = more than 1cm in diameter )is an abnormal growth of cells within the pituitary gland.

Most pituitary tumours are benign (non-cancerous), which means they grow slowly and do not spread to other parts of the body.

However, they can make the pituitary gland produce too many hormones (mine is/was a prolactinoma) which can cause problems in the body.

Tumours that make hormones are called functioning tumours, and they can cause many different symptoms depending upon the hormone affected.

Tumours that don’t make hormones are called non-functioning tumours. Their symptoms depend on how big the tumour is getting and can include headaches, vision problems, nausea, and vomiting.

Diseases that could be caused by abnormalities in the hormones include Cushing’s disease, in which fat builds up in the face, back and chest, and the arms and legs become very thin; and acromegaly, a condition in which the hands, feet, and face are larger than normal.

Pituitary hormones that affect the sex hormones, such as oestrogen and testosterone, can make a woman produce breast milk even though she is not pregnant or nursing, or cause a man to lose his sex drive or lower his sperm count.

Pituitary tumours often go undiagnosed because their symptoms resemble those of so many other more common diseases.

How will I feel?

Most of the symptoms (across all conditions) are a result of a hormone imbalance and can take a long time to develop:

Fatigue/lack of stamina
Menstrual problems (female)
Mood swings
Visual problems
Headache/head pain
Hangover-type feeling, generally feeling unwell
Low libido/vaginal dryness
Loss of hair/pale skin
Sense of negativity/lack of enthusiasm
How will my tumour be diagnosed?

Pituitary tumours are often found as a result of a blood test; for example, after routine blood samples taken to investigate infertility. If excessive amounts of hormones are detected in the blood then a CT scan or an MRI scan will be arranged. The scan will show the exact position of the tumour:

CT brain scan (Computed Tomography) is a specialised x-ray. It will take 10-20 minutes.

MRI brain scan (Magnetic Resonance Imaging) is a specialised imaging technique that gives very clear pictures of the brain and will show the site and extent of the tumour. It usually takes 30 to 40 minutes and uses magnetism instead of x-rays. People with pacemakers cannot have this test and those with any other metallic implants should inform their specialist well before the test.

How will my tumour be treated?

Generally, treatment depends on the type of tumour, the size of the tumour, whether the tumour has invaded or pressed on surrounding structures, such as the brain and visual pathways, and your age and overall health.

Three types of treatment are used: surgery to remove the tumour; radiation therapy, in which high-dose x-rays are used to kill the tumour cells and drug therapy to shrink or destroy the tumour.

Surgery: This is a common treatment for pituitary tumours. The operation is technically easier than for other brain tumours. Generally the surgeon aims to remove most but not all of the pituitary gland. If the pituitary gland does not recover then medication will need to be given to replace the missing hormones. This is not a major problem and is usually managed by a doctor called an endocrinologist.

The surgery for this type of tumour is performed through the nasal cavities

Radiotherapy: This is the use of high energy x-rays to destroy tumour cells. It is often given following surgery. Radiotherapy is usually given as a course of treatments called fractions. This usually means 20-30 treatments, once daily, 5 days a week, for up to 6 weeks. See our section on radiotherapy.

Medication: Drugs are also sometimes used to block the tumour from overproducing hormones.

What is the prognosis?

If detected early, the prognosis is usually very good. However, if there is a delay in diagnosis, even a non-functioning tumour can cause serious problems if it grows large enough to press on the optic nerve, the brain or the carotid arteries ( the vessels that bring blood to the brain.)

Where else can I find information?

For more information on pituitary tumours, see the website for the Pituitary Foundation or contact them at PO Box 1944, Bristol, BS99 2UB, telephone (office) 0845 450 0376 or their Support and Information Help Line: 0845 450 0377 or email helpline@pituitary.org.uk


Click here to read a great fact sheet