Acromegaly

Definition

Acromegaly is a chronic metabolic disorder in which there is too much growth hormone and the body tissues gradually enlarge.

Alternative Names

Somatotroph adenoma; Growth hormone excess; Pituitary giant; Gigantism

Causes

Acromegaly occurs in about 6 of every 100,000 adults. It is caused by abnormal production of growth hormone after the skeleton and other organs finish growing.

Excessive production of growth hormone in children causes gigantism rather than acromegaly.

The cause of the increased growth hormone release is usually a noncancerous (benign) tumor of the pituitary gland. The pituitary gland, which is located just below the brain, controls the production and release of several different hormones, including growth hormone.

Symptoms

• Body odor
• Carpal tunnel syndrome
• Decreased muscle strength (weakness)
• Easy fatigue
• Enlarged bones of the face
• Enlarged feet
• Enlarged hands
• Enlarged glands in the skin (sebaceous glands)
• Enlarged jaw (prognathism) and tongue
• Excessive height (when excess growth hormone production begins in childhood)
• Excessive sweating
• Headache
• Hoarseness
• Joint pain
• Limited joint movement
• Sleep apnea
• Swelling of the bony areas around a joint
• Thickening of the skin, skin tags
• Widely spaced teeth
• Widened fingers or toes due to skin overgrowth with swelling, redness, and pain

Other symptoms that may occur with this disease:

• Excess hair growth in females
• Weight gain (unintentional)

Exams and Tests

• High growth hormone level
• High insulin-like growth factor 1 (IGF-1) level
• Spine x-ray shows abnormal bone growth
• Pituitary MRI may show a pituitary tumor
• Echocardiogram may show an enlarged heart, leaky mitral valve, or leaky aortic valve

This disease may also change the results of the following tests:

• Fasting plasma glucose
• Glucose tolerance test

Treatment

Surgery to remove the pituitary tumor causing this condition corrects the abnormal growth hormone secretion in most patients. This surgery may not be available to patients in remote locations, so travel to a larger metropolitan area may be necessary for treatment.

Radiation of the pituitary gland is used for people who do not respond to the surgical treatment. However, the reduction in growth hormone levels after radiation is very slow.

The following medications may be used to treat acromegaly:

• Octreotide (Sandostatin) or bromocriptine (Parlodel) may control growth hormone release in some people.
• Pegvisomant (Somavert) directly blocks the effects of growth hormone, and has been shown to improve symptoms of acromegaly.

These medications may be used before surgery, or when surgery is not possible.

After treatment, periodic evaluation is necessary to ensure that the pituitary gland is working normally. Yearly evaluations are recommended.

Outlook (Prognosis)

Pituitary surgery is successful in most patients, depending on the size of the tumor and the experience of the surgeon.

Without treatment the symptoms will get worse, and the risk of cardiovascular disease increases.