Growth hormone is secreted by the anterior lobe of pituitary gland under the influence of growth hormone releasing hormone which is secreted by the hypothalamus.
Causes of acromegaly.In 90% of cases, the cause of growth hormone excess or acromegaly is Pituitary adenoma while other 10% causes include; Ectopic secretion of growth hormone or growth hormone releasing hormone by some tumor.
Diagnosis of Acromegaly
It is diagnosed by the clinical features, which include; large spade-like hands, frontal bossing, large jaw and gigantism. IGF 1 and growth hormone level are raised and MRI of brain usually show pituitary adenoma.
Treatment of Acromegaly.
Any of the following regimens can be tried.
- Surgery is the first line: Transsphenoidal resection of pituitary adenoma is the first line treatment, and usually cure the disease.
- Dopamine agonists, for example, bromocriptine was the first line therapy, but now superseded by the octreotide. Octreotide is effective in 50-70% of cases and may be used as an adjunct to surgery.
- Pegvisomant is the newer drug which is growth hormone receptor antagonist and it is very effective and it decreases IGF1 levels in 90% of cases. But it has no effect on tumor size and surgery should be done to remove the pituitary adenoma.
- External radiation are used when surgery or medical therapy fails.