A disorder caused by the increased secretion of growth hormone by an ADENOMA of the anterior PITUITARY GLAND. It results in excessive growth of both the skeletal and the soft tissues. If it occurs in adolescence before the bony epiphyses have fused, the result is gigantism; if it occurs in adult life the skeletal overgrowth is conﬁned to the hands, feet, cranial sinuses and jaw. Most of the features are due to overgrowth of the cartilage of the nose and ear and of the soft tissues which increase the thickness of the skin and lips. Viscera such as the thyroid and liver are also aﬀected. The overgrowth of the soft tissues is gradual.
The local eﬀects of the tumour commonly cause headache and, less frequently, impairment of vision, particularly of the temporal ﬁeld of vision, as a result of pressure on the nerves to the eye. The tumour may damage the other pituitary cells giving rise to gonadal, thyroid or adrenocortical insuﬃciency. The disease often becomes obvious in persons over about 45 years of age; they may also complain of excessive sweating, joint pains and lethargy. The diagnosis is conﬁrmed by measuring the level of growth hormone in the serum and by an X-ray of the skull which usually shows enlargement of the pituitary fossa.
Treatment The most eﬀective treatment is surgically to remove the pituitary adenoma. This can usually be done through the nose and the sphenoid sinus, but large adenomas may need a full CRANIOTOMY. Surgery cures about 80 per cent of patients with a microadenoma and 40 per cent of those with a large lesion; the rate of recurrence is 5–10 per cent. For recurrences, or for patients unﬁt for surgery or who refuse it, a combination of irradiation and drugs may be helpful. Deep X-ray therapy to the pituitary fossa is less eﬀective than surgery but may also be helpful, and recently more sophisticated X-ray techniques, such as gamma knife irradiation, have shown promise. Drugs – such as BROMOCRIPTINE, capergoline and quiangoline, which are dopamine agonists – lower growth-hormone levels in acromegaly and are particularly useful as an adjunct to radiotherapy. Drugs which inhibit growth-hormone release by competing for its receptors, octeotride and lanreotride, also have a place in treatment.
See www.niddk.nih.gov/health/endo/pubs/ acro/acro.htm