A B C D E F G H I J K L M N O P R S T U V W

ACROMEGALY

What is Acromegaly ?

The pituitary is a pea-sized gland located behind the root of the nose and attached to the base of the brain. Its cells control the functions of other organs, including the thyroid, the adrenal and the sex glands. However, one group of its cells also produces growth hormone. This is the main regulator of growth in children. In acromegaly, these cells multiply to produce a small benign (non-cancerous) tumour. This results in the pituitary gland making too much growth hormone. If this tumour occurs in children, growth is stimulated and they become very tall. However, mostly the condition occurs in adults, who do not become taller because the long bones of the arms and legs are already mature. But it does lead to thickening and widening of tissues, including the skin and the bones. The hands and feet enlarge and the head enlarges or becomes very angular.

Even the heart and the abdominal organs may enlarge. Excessive sweating and skin greasiness are due to stimulation of the skin and its structures by growth hormone. A variety of muscle and bone pains are produced by the overgrowth of tissues, especially near the joints. Breathlessness and tiredness may occur because of disturbed function of muscles in the heart and limbs. Diabetes develops in some people, due to the increase in blood-sugar level produced by the growth hormone. Drowsiness by day is quite common. This is due to disordered sleep, in turn resulting from breathing difficulties (obstructive sleep apnoea). Occasionally there may be no symptoms at all.

If the benign pituitary tumour enlarges sufficiently, it can press on the optic nerves which transmit messages from the eyes to the brain. This can cause blind spots in the field of vision. Such enlargement may also interfere with other hormone functions of the pituitary gland, resulting in tiredness and a variety of other problems.

How does Acromegaly occur ?

There is no single cause. The responsible cells of the pituitary probably begin multiplying many years before the condition becomes obvious.

Why does Acromegaly occur ?

No one knows. Only about one person in 20 000 has this uncommon disorder.

Treatment Involved for Acromegaly

The doctor will decide how active the condition is by measuring the level of the growth hormone in special blood samples. He or she will also do other blood tests to gain an idea of the wider effects of the tumour. An (MRI) scan is performed. This uses a high powered magnetic field to see the size and position of the pituitary tumour.

Occasionally, no treatment is needed, particularly in very advanced age. Medical treatment consists of giving a drug which reduces the production of growth hormone without necessarily affecting the size of the tumour. This may be given by mouth as tablets called dopamine agonists. A different group of drugs which are more effective are given by injection : octreotide needs to be given three times a day, but depot injections (Lanreotide, Sandostatin-LA) given monthly are probably more effective (and convenient).

Tablets or injections may also be needed to replace a shortage of hormones resulting from damage to other parts of the pituitary gland by the tumour. In particular, thyroid hormones and cortisone-like tablets may be needed, as well as injections or tablets of sex hormones.

Surgical treatment is often used to remove the pituitary tumour. Unless the tumour is particularly large, this is done by a neurosurgeon by an approach through or near the nose, shelling out the tumour and leaving behind as much of the normal pituitary as possible. This is quite a small procedure performed under general anaesthetic. Larger tumours need to be removed by an approach through the skull. Radiotherapy is occasionally used by itself, with treatment provided over approximately 20 sessions during a period of a month or so. The response to this is often quite slow. More often, the radiotherapy is used to mop up remaining cells which the surgeon was not able to remove completely at the time of the operation.

During Treatment for Acromegaly

Any prescribed medicines must be taken absolutely regularly, according to the advice given by the doctor. The only side-effects are occasional nausea and diarrhoea produced by some of the drugs used to treat the acromegaly. Both the depot drugs mentioned earlier increase the risk of developing gallstones. After any operation on the pituitary, tests will be done to see whether the operation has accidentally interfered with other hormone levels in the blood. It may be that either hydrocortisone or thyroxine need to be taken.

After Treatment for Acromegaly

After a successful operation, there may be quite a striking initial loss of fluid through the urine. After a few months, the skin gets softer, and abnormal sweating disappears. If diabetes was present, it may get better or even disappear. Over a period of years the enlargement of hands, feet and head slowly reverses, and general wellbeing returns. Similar changes may occur after medical treatment. On the other hand, radiotherapy has a much slower effect: it may take 10 or more years before any improvement is seen. No particular problems need be expected from any cortisone or thyroxine replacement treatment. However, the cortisone dose needs to be doubled or tripled with certain illnesses. It may also need to be given by injection if vomiting occurs due to any other cause. If in doubt, the doctor must be notified.

If Acromegaly Left Untreated

In rare cases, the condition either remains stable or can « burn itself out » (probably due to the tumour outgrowing its blood supply). However, untreated acromegaly usually progresses in severity, producing greater or lesser degrees of disfigurement, tiredness, joint pains, and occasionally heart failure and sudden death. Damage to eyesight is a particular concern, resulting from the increasing size of the pituitary tumour which can press on the optic nerves.

Effects on Family of Acromegaly

They may notice a return of your normal appearance over a period of years. Once tablets are started, never stop them unless the doctor advises it.