ACROMEGALY

What is acromegaly?

This is a disease caused by the excessive levels of Growth Hormone (called GH) in an adult. When it occurs in a child the high levels of GH cause fast growth and is then called Gigantism. It is caused by excessive production of Growth Hormone from an abnormal growth in the pituitary gland.

It is a small pea size gland situated in a hollow bony pouch, at the base of the brain, at the back of the bridge of the nose. It is the master gland of the endocrine system and controls the functions of the other endocrine glands in the body.

An abnormal growth of the pituitary gland is called an adenoma. It usually grows very slowly over many years. The pituitary gland sits in a very limited space and surrounded by the very important structures including blood vessels and nerves. Therefore, when an adenoma enlarges it can have a compression effect on the normal pituitary tissue which then fails to work properly. Gradually the expansion of the adenoma can press on surrounding areas causing headache and disturbed vision.

It is a hormone produced by the pituitary and has effects on the various tissue of the body. In children, it is essential to reach normal growth. In adult, it is important to keep up with normal energy level and to keep body tissues (e.g. muscles, bones) healthy.

It is very rare, four new cases per one million people per year.

1. Symptoms develop due to an increased secretion of growth hormone,

Change in appearance from old photos; facial features become more coarse.
Increased in shoe size requirement as feet enlarge in width
Increase in size of hands. Rings on fingers become very tight.
Lower jaw expands outwards causing trouble with the teeth and clicking as one eats
Nose and tongue enlarge with sinus problems
Profound tiredness, falling asleep at any time and yet a restless sleep with snoring
Thick, greasy skin
Excessive sweating
Deepening voice
Muscle weakness
Joint pains
Tingling sensation especially in hands due to trapped nerves
High blood pressure
Diabetes mellitus.

Headache
Disturbed vision; double vision, poor vision
Underproduction of other pituitary hormones causing irregular or absent menstrual periods, impotence and infertility

Why do Acromegalic patients need treatment?

• Studies show that untreated Acromegalic patients are more likely to suffer from high blood pressure, diabetes, stroke, and heart attack with reduced life expectancy compared to the normal population. This can be improved after the successful treatment of Acromegaly.
• The growth of the tumour can cause pressure effects on the surrounding structures with symptoms such as the visual troubles mentioned above which can be relieved by treatment
• Effects of the excess GH on the different body tissue can cause many symptoms as mentioned above which treatment relieves.

1. To confirm whether the patient is producing excessive GH, the specialist usually perform an ORAL GLUCOSE TOLERANCE TEST with measurement of GH after the sugary drink.

2. Blood test to check for certain other hormones which may be affected by the expanding pituitary adenoma such as thyroid and sex hormones.

3. You might also require to have a special test to check in detail the functioning of the pituitary called the Complete Pituitary Function Test.

4. You will also need to have the field of vision checked to assess whether the adenoma is having a pressure effect on the major nerve carrying information from the eye to the brain which enables you to see. This nerve passes very close to the pituitary gland.

5. You will require a special scan (MRI) of the pituitary to check the size of the pituitary adenoma and the surrounding structures such as the eye nerves.

Surgery
Removal of the GH producing pituitary adenoma with Trans Sphenoidal Pituitary Surgery (TSS). In some situations where the pituitary tumour is too big to remove by TSS an actual opening of the skull called a craniotomy may be required. Surgery is successful in curing small tumours but less effective with large ones where radiotherapy is usually required.

External Radiotherapy
Radiotherapy is used to prevent recurrence and also to further treat large adenomas which have not been cured by surgery. The radiotherapy is usually given as small dosages every alternate day over about 4 weeks so as to have a maximum effect on the pituitary without damaging surrounding structures. Radiotherapy can take some years to work effectively and here medical therapy may be advised.

Medical Treatment
Medical therapy is usually used to reduce the symptoms of excess GH while awaiting for radiotherapy to work. It is also used in certain patients who to prepare for surgery.
Bromocriptine is taken by mouth but regrettably is effective in about 15% of patients. Newer and more effective medicines are now available but have to be given by injection. Sandostatin is given as an injection three times per day but recently a long acting form (Sandostatin LAR) has been issued which can be given every 28 days. Another medicine is called Lanreotide. This is given by injection every 7-14 days.

Hormone Replacement Therapy
During pituitary surgery often the normal pituitary has to be removed to allow access and successful removal of the adenoma although the surgeon does try to preserve as much normal pituitary as possible. In large adenomas it may be impossible to both remove the adenoma and preserve any normal pituitary. Radiotherapy is also likely to cause under functioning of the whole pituitary gland after a few years. In the above situations, you will require life long hormone replacement therapy, which may include hydrocortisone, thyroxine, antidiuretic hormone called DDAVP, male hormone replacement in tablets, injection or in patches, and hormone tablets in females.

 Tests after the surgery and radiotherapy

You will need life long follow up by a specialist. Certain tests will be carried out as required;

1. Re-assessment of GH level after the surgery with oral GLUCOSE TOLERANCE TEST with measurement of GH levels.
2. Assessment of the other pituitary hormones to assess whether they are working. This is usually done some six weeks after the surgery and /or radiotherapy (known as COMPLETE PITUITARY FUNCTION TEST).
3. Blood IGF1 measured which reflects the long term average GH level
4. Repeated MRI scan to check for recurrence.
5. If your GH level remains high and requires medical treatment, the specialist may check the level of GH at different times of the day before adjusting the dose requirement of Sandostatin or Lanreotide.

ADDITIONAL POINTS

1. If you require life long replacement therapy after the surgery, you will get free prescription.
2. If you require cortisol replacement, you will require to increase the dose at the time of acute illness, you should carry a steroid card and medi-bracelet and should always inform any doctor of your replacement therapy.
3. You should inform the DVLC and Insurance Company of your condition.
4. General appearance often shows much improvement after the successful treatment of Acromegaly although it may take some years. Arthritic joints may not improve and may need therapy in later life
5. You may have very little or no normal cortisol production after the surgery and may require hydrocortisone, which is a steroid medicine. The dose will be adjusted to replace the normal requirement of the body.
6. It is very important to have regular follow up by a specialist so that your condition can be monitored closely.
7. Life expectancy after the successful treatment of early acromegaly is the same as normal population.

The Pituitary Foundation
PO Box 1944
Bristol, BS99 2UB.
Tel/Fax 0117 927 3355
e-mail- helpline@pitpat.demon.co.uk

or www.pituitary.org.uk

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Ó NHS Tayside; 2006; version 1.0

Disclaimer; no liability whatsoever is accepted for information given and all such information, especially with regard to drug usage (UK version provided), must be checked with a person’s health provider.