Acromegaly

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
• Excessive height (when excess growth hormone production begins in childhood)
• Excessive sweating
• Headache
• Hoarseness
• Joint pain
• Large bones of the face
• Large feet
• Large hands
• Large glands in the skin (sebaceous glands)
• Large jaw (prognathism) and tongue
• 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 too much skin growth, 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 that is causing this condition usually corrects the abnormal growth hormone release in most patients. Sometimes the tumor is too large to remove completely. People who do not respond to surgery will have radiation of the pituitary gland. 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, after surgery, or when surgery is not possible.

After treatment, you will need to see your health care provider regularly to make sure 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 high blood pressure, diabetes (high blood sugar), and cardiovascular disease increases.

Possible Complications

Other health problems may include:

• Arthritis in most joints, which along with excess bone growth may put pressure on the nerves of the spine or the spinal cord   
• Carpal tunnel syndrome
• Colonic polyps
• Hypopituitarism
• Sleep apnea     
• Uterine fibroids
• Vision problems

When to Contact a Medical Professional

Call your health care provider if:

• You have symptoms of acromegaly
• Your symptoms do not improve with treatment

Prevention

There are no methods to prevent the condition, but early treatment may prevent complications of the disease from getting worse.

Alternative Names

Somatotroph adenoma; Growth hormone excess; Pituitary giant

References

Melmed S, Kleinberg D. Pituitary masses and tumors. In: Kronenberg HM, Melmed S, Polonsky KS, Larsen PR, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 9.

Update Date: 12/11/2011

Updated by: Nancy J. Rennert, MD, Chief of Endocrinology & Diabetes, Norwalk Hospital, Associate Clinical Professor of Medeicine, Yale University School of Medicine, New Haven, CT. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.