ACROMEGALY A disorder caused by ihc increased secretion of growth hormone by an adenoma of the anterior pituitary gland. It results in excessive body 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 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 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 consists of removal or irradiation of the pituitary adenoma. This may have to be done via a craniotomy if the tumour is large but can often be done by an approach through the nose and sphenoid sinus. Deep X-ray therapy to the pituitary fossa is also effective treatment but it may take several years for irradiation to achieve its maximum effect. Drugs, such as bromocriptine, which are dopamine agonists, lower growth hormone levels in acromegaly and are particularly useful as an adjunct to radiotherapy.