12th April 2024

Acromegaly

Acromegaly is an endocrine disorder characterised by the excess of growth hormone production. Typically caused by pituitary gland tumours or hyperplasia, it can also be a result of ectopic production from other sources, such as carcinoid tumours. Common signs and symptoms include excessive growth of hands (spade hands), feet and tongue, tired demeanour involving puffy facial features, coarsening of the face and supraorbital ridges, reduced libido, obstructive sleep apnoea and arthralgia. Gigantism, a form of acromegaly in children, occurs due to excessive growth before the completion of epiphyses fusion. Acromegaly increases the risk of colon cancer, IHD, CVA and diabetes.

Investigations

Serum IGF-1 is used as an initial screening test and is more reliable than GH as it can vary during the day. The oral glucose tolerance test (OGTT) is used to confirm after a positive screening test. It consists of fasting the patient overnight and giving glucose supplementation in the morning with serial GH measurements, as glucose should inhibit GH. A diagnosis is made if the glucose load does not suppress GH <1 microgram/litre. All these tests can be affected by puberty, pregnancy, anorexia, liver/renal diseases or diabetes.

An MRI scan of the pituitary and hypothalamus may demonstrate a tumour. Visual field testing allows assessment for any abnormalities and echocardiography for acromegaly-associated cardiomyopathies.

Management

The management consists of removing the tumour, with the majority having transsphenoidal surgery. Medical therapy can be undertaken with or without prior surgery and includes somatostatin analogues (octreotide/lanreotide) and GH antagonists (pegvisomant). In select patients with aggressive disease or when medication is ineffective, radiotherapy can also be considered.