Pituitary adenoma

A pituitary adenoma is a tumour that develops from the tissue of the pituitary gland. The pituitary gland is found towards the base of the brain. It controls other glands within the body that in turn control many of the body's functions.

What is a pituitary adenoma tumour?

Pituitary adenomas don't fall under the category of brain and central nervous system tumours. Instead they are tumours of the endocrine system which is responsible for the secretion or release of various hormones into the bloodstream. Most pituitary adenomas are benign and are in fact quite common, with 1 in 5 people estimated to have one at some point in their life. In many cases the growth is harmless and is only diagnosed by chance during scans for other conditions. In some cases however, a pituitary adenoma can cause more serious symptoms.

Although technically not part of the brain, the pituitary is attached to the base of the brain and works with parts of the brain, such as the hypothalamus, affecting their functions.

A pituitary tumour, therefore, though not strictly a brain tumour, has many similar symptoms and side-effects. It may also grow upwards and press on the brain and its nerves.

For these reasons, all our information and support services are available to people with pituitary tumours.

What are the symptoms of a pituitary adenoma?

There are two ways in which a pituitary adenoma can cause symptoms:

Hormone production

Our hormones regulate a lot of important bodily functions and processes. Some pituitary adenomas cause over-production or under-production of hormones. Possible symptoms of hormone-producing adenomas include:

From over-production

• Loss of menstrual periods in women
• Lowering of testosterone in men leading to loss of sexual appetite
• Acromegaly in adults and gigantism in children which cause extreme growth spurts and growth of hand and feet respectively
• Unexpected weight gain
• Easy bruising of the skin and muscle weakness

From under-production

• Loss of sex drive in men and women and infertility
• Hypothyroidism, which can cause appetite loss, weight gain, fatigue and decreased mental function
• Adrenal insufficiency which can cause fatigue, low blood pressure, electrolyte abnormalities
• Growth hormone insufficiency which can cause delayed puberty and in adults tiredness and loss of muscle mass

The size of the tumour

Like with brain tumours in other areas of the brain, the growth of a pituitary adenoma can put pressure on surrounding tissue causing and especially the optic nerve causing vision loss or loss of peripheral (side) vision and other related problems. An increase in the pressure surrounding the optic nerve can be identified during an eye test.

How are pituitary adenomas treated?

If the only symptom of the tumour relates to the levels of hormones produced, the condition can be managed by medication (usually given by a neuro-endocrinologist) used to stabilize hormones to normal levels. Surgery (often non-invasive) and stereotactic radiosurgery (a form of radiotherapy) will be used if there is a need to remove or control the growth of the tumour. You can ask your doctor or medical team about the treatment options for this type of tumour.