Acromegaly is a rare hormonal disease caused by excessive secretion of growth hormone by the pituitary gland. This gland (a pea-sized organ situated just beneath the brain) is by far the largest of the endocrine (hormone-producing) glands. The hormones it produces regulate many of the body’s processes.
Acromegaly Caused By A Tumor In The pituitary Gland
Growth hormone stimulates cell division and the development of protein in tissues such as bone, cartilage, and muscle. If there is too much of this hormone in the bloodstream, it can lead to abnormal enlargement of various parts of the body.
Enlarged hands are characteristic of acromegaly, which is usually caused by a benign tumor of the pituitary gland that affects growth.
This usually includes enlargement of the hands, feet, head, neck and facial features. These symptoms usually appear gradually over several years.
Acromegaly occurs in both men and women and is more common in middle age. Average age at diagnosis is about 40 years in men, and 45 years in females.
- Enlargement of hands and feet.
- Broadening of head and neck.
- Prominent lower jaw, brow, nose and ears. Thickening of skin and tongue.
- Deeper voice. Increased body hair in women.
- Tingling in hands and feet.
- Joint pains.
- Fatigue increased sweating.
What Causes Acromegaly?
In about 95% of cases, acromegaly occurs as a result of a benign tumor of the pituitary gland. In rarer cases, the excess growth hormone is produced by a tumor growing in another part of the body, such as the pancreas, lung, ovary or breast.
Growth hormone secreting tumors that appear before the age of 15 results in a condition called gigantism, in which growth of the entire body is exaggerated.
However, more commonly the tumor develops later in life after the long bones of the limbs have stopped growing.
Therefore, since an adult cannot grow taller, the main effect of the excess growth hormone is to cause bones to thicken and other structures and organs to become enlarged.
Acromegaly is diagnosed using specialized tests that are performed in a hospital, usually in an endocrine department (a unit which specializes in disorders of the endocrine system).
Blood tests will be carried out to measure the level of growth hormone in the blood. These may include tests to measure growth hormone levels at intervals during the day.
Other blood tests involve measuring the level of growth hormone before and after being given glucose. Glucose usually suppresses the production of growth hormone.
If the level is not decreased after glucose has been given, it is confirmation that the pituitary gland is secreting too much of the hormone.
Also, special X-rays, such as a CT scan (computerized tomography) or MRI scan (magnetic resonance imaging) may be carried out to reveal a tumor of the pituitary gland.
A CT scan combines the use of a computer and X-ray technology to produce a clear cross-section of the tissue being examined. MRI provides high-quality cross-sections of the brain without using X-rays.
There are three options for treatment: drug therapy, surgery, or radiation, but often a combination of all three is needed. The form of treatment depends on how far the condition has developed and the size and type of any tumor.
Drug therapy to suppress the secretion of growth hormone is the first line of treatment in most cases. Octreotide, given as an injection under the skin, is effective at both reducing the amount of growth hormone being produced and at shrinking the pituitary tumor.
There is usually an improvement in the symptoms of acromegaly after starting this therapy. The an-other drug, bromocriptine, can also suppress the secretion of growth hormone. But it is not as effective as octreotide and may cause unpleasant side effects.
Surgery to remove the tumor often results in a rapid reduction in growth hormone levels and cessation of soft tissue enlargement, but it may not produce a complete cure.
The tumor may recur several years after surgery if the original tumor has not been completely removed, or if a new tumor has formed. In some cases, surgical damage to the remaining part of the pituitary gland leads to pituitary failure and may require lifelong hormonal replacement treatment.
Radiotherapy can also be used to shrink the tumor. After this type of treatment, it may take several years to the level of growth hormone to return to normal. Pituitary failure may also occur and, again, hormone replacement may be needed.
What Is Pituitary Gland?
The pituitary is the master gland in the body and has numerous connections which link it with a part of the brain called the hypothalamus.
It not only produces hormones to initiate processes such as growth directly, but it also works indirectly by triggering other hormone-producing organs, such as the thyroid and adrenal glands, and the sex organs.
Other functions stimulated by the pituitary include:
Water retention (by acting on the kidneys).
When Should I See My Doctor?
See a doctor if you notice any symptoms of acromegaly. The longer the condition is left untreated, the greater the risks from associated conditions such as hypertension (high blood pressure), diabetes meal lists and heart failure.
Acromegaly can be fatal if left untreated or is only partially treated. If the heart continues to enlarge, hypertension or heart failure may occur.
Diabetes and lung infections may also develop. Also, a large tumor in the pituitary gland can cause other problems, such as loss of eyesight.
In many cases, treatment can stop further abnormal growth and reverse some of the symptoms. Much depends on how long the condition has existed and on the severity of the symptoms, though with modern treatment there will be an improvement.