An abnormal growth (Adenoma) can develop from the pituitary gland. This adenoma may, or may not actively produce any hormones. It normally grows very slowly and does not spread throughout the body. The pituitary gland sits in a very limited space and is surrounded by some very important structures. Therefore, any enlargement or growth can have pressure effects upon the pituitary gland itself and also upon the surrounding area. This local pressure can cause headaches and visual disturbances and the disruption of hormone production can have subsequent systemic effects on the body.

Growth hormone is produced by the pituitary and has important effects on the various tissues of the body. In children, it is an essential element in achieving normal growth. In adults it is important for maintaining normal energy levels and for keeping body tissue (e.g. muscles and bones) healthy.

The Hypothalamus is that part of the brain which controls pituitary function. It releases hormones, which stimulate (GHRH), and Somatostatin, which blocks the release of GH and so acts against overproduction from the pituitary.

It is a very rare condition, diagnosed in only four per million of the population each year.

Symptoms, which are due to the increased levels of GH acting upon the tissues:

Appearance changes can be subtle and not always noticed by the patient or their family members:
Facial features coarsen as the skin becomes thicker and greasier.
There is an increase in size to the hands, feet, lower jaw, nose and ears (noticed as an increase in glove size, shoe size or a wedding ring that has become too tight.)
Sweating can be excessive and the voice deepens.
There is also muscle weakness, joint pain and a tingling sensation, which is due to nerves being trapped by enlarged tissues e.g. Carpal Tunnel Syndrome.
There is also a greater risk of high blood pressure and diabetes.

Symptoms, which are due to the enlarged pituitary affecting the surrounding structures:

These include headaches, visual disturbances and sinus problems.
Sleep apnoea can also be a symptom along with the resultant tiredness caused by disturbed sleep.
Underproduction of other pituitary hormones may cause, irregular periods, breast secretions or impotency.

Studies show that untreated Acromegalic patients are more likely to suffer from high blood pressure, diabetes, stroke and heart attack, with a reduced life expectancy when compared to the normal population. This returns to normal after successful treatment. The growth of the tumour can cause pressure effects on the surrounding structures with intolerable symptoms. Symptoms related to the effects of the excess GH on the different body tissue could also become intolerable.

Tests:

Normally, GH levels are very low and vary throughout the day.

Surgery

Removal of the GH producing pituitary adenoma using Trans Sphenoidal Surgery, (TSS), or very rarely, when tumours are very large, with Craniotomy.

External Radiotherapy.

In the case of a large tumour or, if the GH production remains in excess after the surgery then radiotherapy will be required.

Medical Treatment.

Medicines can be used to block the action of GH production. This is usually required whilst awaiting the effects of the radiotherapy, which may take a few years to complete its work. Sandostatin or Bromocriptine can be used to do this. The first is more commonly effective but requires injection and is expensive. Dose and frequency of injections is dependent on measured GH levels.

Hormone Replacement Therapy:

In the above two situations, patients will require life long Hormone Replacement Therapy (HRT). This may include the following:
Hydrocortisone; Thyroxin; Antidiuretic Hormone (ADH); Testosterone; and the female hormones Oestrogen and Progestogen. (See also Hypopituitarism)

Tests following surgery.

Additional points.