Acromegaly is excessive bone growth. It results when a person's body produces too much growth hormone. The condition causes gradual enlargement of the bones in the face, jaw, hands, feet, and skull.
What is going on in the body?
Most cases of acromegaly are caused by a pituitary tumor that is benign, which means that it is not cancer. The tumor causes the pituitary gland to make excess growth hormone. The high level of the hormone produces changes in many tissues and organs. Acromegaly occurs after growth has been completed. In most cases, it begins between the ages of 30 and 50.
What are the causes and risks of the condition?
The high growth hormone levels that lead to acromegaly are usually caused by a pituitary tumor. No one knows what causes pituitary tumors. They are more common in women than in men.
What can be done to prevent the condition?
There is no prevention for acromegaly. However, early treatment may prevent the worsening of any complications from the condition.
How is the condition diagnosed?
Diagnosis of acromegaly begins with a medical history and physical exam. It may take years after the first symptoms appear to diagnose acromegaly. This is because the changes occur so slowly.
A blood test to measure the levels of human growth hormones, called HGH, is helpful in diagnosis. Many people with acromegaly develop high blood sugar levels, so this sign may prompt a doctor to investigate further.
Skull X-rays, a cranial CT scan, or a cranial MRI can reveal a problem with the pituitary gland. Bone X-rays can show thickening of the skull and the long bones of the body. X-rays may reveal some arthritis in the spine as well.
Long Term Effects
What are the long-term effects of the condition?
A person who has untreated acromegaly usually has a reduced life expectancy and may develop premature heart disease.
What are the risks to others?
Acromegaly is not contagious and poses no risks to others.
What are the treatments for the condition?
The goal of treatment is to stop the body from producing so much growth hormone.
There are three treatment approaches:
- Surgery. When the pituitary tumor is removed, it usually corrects the abnormal growth hormone secretion. This is the initial treatment in most people.
- Medicine. Medicines such as octreotide (i.e., Sandostatin) and bromocriptine (i.e., Parlodel) may be used to block the production of growth hormone.
- Radiation therapy. Radiation therapy helps to shrink the pituitary tumor and thus reduces the secretion of growth hormone.
What are the side effects of the treatments?
Surgery may cause bleeding, infection, and allergic reactions to the anesthesia. About one-third of people who are given medicines to block the production of growth hormones have side effects. Side effects include pain at the injection site, loose stools, abdominal pain, and gallbladder stones.
Radiation may cause mouth ulcers. In addition, by damaging the normal tissues around the tumor, it can lead to reduced production of other pituitary hormones. However, accurate targeting of the radiation can reduce these effects.
What happens after treatment for the condition?
When treatment is a success, the excess bone growth should stop. There is a slight chance that the tumor that caused the acromegaly may come back.
How is the condition monitored?
The person should have yearly medical exams. Blood tests may be performed to measure the amount of growth hormone present and make sure that it stays in a healthy range. Any new or worsening symptoms should be reported to the doctor.
The Merck Manual of Medical Information, Home edition, 1997
Professional Guide to Diseases, Sixth Edition. Springhouse: Springhouse Corporation, 1998.
Tierney, Lawrence, editor, "Current Medical Diagnosis and Treatment, 39th edition", 2000