Pituitary gland tumours are brain tumours that start to grow in the the pituitary gland. Most pituitary tumours are non cancerous (benign). Benign pituitary gland tumours are also called pituitary adenomas.
The pituitary gland is a small gland that lies in a hollow, just behind the eyes. It controls many body functions by making and releasing hormones into the bloodstream.
The pituitary gland is part of our endocrine system. So pituitary gland tumours are also called pituitary neuroendocrine tumours (PitNETs).
Types of pituitary tumours
Pituitary tumours can be put into 2 groups depending on whether they make hormones or not.
The symptoms you have depend on whether the tumour makes hormones or not.
Pituitary tumours that don’t make hormones
Pituitary tumours that don't make hormones are usually larger than tumours that produce hormones. They can press on the nearby optic nerve and cause changes to your eyesight. They can also affect the normal pituitary gland tissue so that you have changes in the levels of hormones.
Pituitary tumours that make hormones
There are a number of different types of pituitary tumours that make hormones. These tumours can cause quite unusual symptoms depending on the type of hormone they produce.
Prolactinomas make a hormone called prolactin which regulates the milk production after pregnancy. They are the most common type of functioning pituitary tumours. They are also called lacotroph adenomas.
Prolactinomas can cause:
- menstrual periods to become less frequent or stop
- loss of sex drive
- difficulty getting an erection
- increased milk production in the breasts of women
Tumours that make growth hormone are also called somatotroph adenomas. They can cause a condition called acromegaly. Symptoms of acromegaly include:
- growth spurts in young people
- overgrowth of hands, feet and lower jaw in adults
ACTH stands for adrenocorticotropic hormone. ACTH stimulates the adrenal glands to make another hormone called cortisol. These tumours are also called corticotroph adenomas.
Tumours that make ACTH can cause a number of symptoms that are known as Cushing’s syndrome. Symptoms include:
- weight gain
- red and rounded face
- high blood pressure
Pituitary tumours that make TSH are also called thyrotroph adenomas. They make too much thyroid-stimulating hormone (TSH). This causes the thyroid gland to make high amounts of thyroid hormones.
You can get symptoms of an overactive thyroid gland (hyperthyroidism) such as:
- weight loss
- tremor (shaking)
- a fast heart beat (palpitations)
How common it is
About 17 out of every 100 brain tumours (about 17%) diagnosed are pituitary tumours.
Most pituitary tumours are benign (not a cancer). They usually grow slowly and tend not to spread.
What tests will I have?
Your doctor examines you and checks your symptoms. You also have tests to diagnose a pituitary tumour. This helps your doctor plan the treatment. The tests you might have include:
- blood tests
- MRI scan or CT scan
The treatment you need depends on the type of pituitary tumour you have. It also depends on how well you are and your symptoms.
Pituitary tumours usually grow slowly over some years. So for a small tumour that isn’t causing symptoms, your doctor might monitor you with regular MRI scans. This is called active monitoring. You then have treatment if there are signs that the tumour is growing or starts to cause symptoms.
Surgery is the most common treatment for pituitary tumours. A highly specialised doctor (neurosurgeon) removes as much of the tumour as possible.
Your surgeon passes a tube into your nose to remove the tumour. This operation is called an endoscopic transphenoidal resection.
Radiotherapy uses high energy x-rays to kill tumour cells. You might have radiotherapy after surgery to kill any tumour that has been left behind. Or you might have if you can't have surgery for any reason.
You may have a type of radiotherapy called external beam radiotherapy or stereotactic radiotherapy.
For some types of pituitary tumours you might take drugs to reduce hormone levels. For example for a prolactinoma, you may take a drug called cabergoline. It stops the pituitary tumour from making the hormone prolactin.
This won’t get rid of the tumour but it might shrink it, and it helps to reduce the symptoms.
You have hormone replacement tablets if you had all or most of the pituitary gland removed during surgery. Hormone replacement includes:
- thyroid hormones
- the sex hormones oestrogen and androgen
- growth hormone
You have hormone replacement as tablets, injections or patches.
If your pituitary tumour comes back, you might be able to have more surgery or radiotherapy. Your doctor might also suggest a chemotherapy drug called temozolomide.
You have regular appointments with your doctor or nurse after treatment finishes. Your doctor examines you at each appointment. They ask how you are feeling, whether you have had any symptoms or side effects, and if you are worried about anything. You might have hearing tests. And you might also have MRI scans on some visits.
How often you have check ups depends on your individual situation.
Coping with pituitary tumours
Coping with a diagnosis of a brain tumour can be difficult, both practically and emotionally. It can be especially difficult when you have a rare tumour. Being well informed about the type of tumour you have, and its treatment can make it easier to cope.
Research and clinical trials
Doctors are always trying to improve the diagnosis and treatment of brain tumours. As part of your treatment, your doctor might ask you to take part in a clinical trial. This might be to test a new treatment or look at different combinations of existing treatments.