Acromegaly is a rare hormonal condition that causes adult bone deformity and many complications of the internal organs and muscles. Because it gradually progresses, it often goes unnoticed and untreated until complications arise.
Overproduction of GH
It usually begins between the ages of 30 and 50 when the pituitary gland overproduces growth hormone (GH). The overproduction of GH is usually a result of a benign tumor on the pituitary gland, but it can be caused by tumors in other areas of the body. When caused by a tumor on the pituitary gland, GH travels via the bloodstream to the liver where it produces another growth hormone called IGF-I.
When produced in other parts of the body, another type of GH causes the release of more growth hormones from the pituitary gland. GH from both pituitary and non-pituitary tumors result in the overgrowth of bone and soft tissues that cause skeletal deformities and a host of major health problems.
The symptoms of acromegaly can go unrecognized for years.
Growth is controlled by the amount of growth hormone (GH) produced in the pituitary gland, which is located at the base of the brain behind the bridge of the nose. GH is secreted into the bloodstream where it causes the liver to produce a hormone called “insulin-like growth factor-I” (IGF-I). IGF-I stimulates bone and tissue growth. When the pituitary gland overproduces growth hormone, too much IGF-I is produced and abnormal growth occurs in soft tissues and the skeleton.
A common cause of GH overproduction in adults arises from tumors.
Pituitary tumors account for most cases of acromegaly in adults. The benign (noncancerous) tumors of the pituitary gland produce excessive amounts of GH, causing symptoms of acromegaly. Some symptoms such as headaches and impaired vision arise from the pressure of the tumor mass on surrounding brain tissue.
Nonpituitary tumors are those that occur in other parts of the body. Tumors in the lungs, pancreas, or adrenal glands can cause acromegaly by secreting GH. In other cases, nonpituitary tumors produce a growth hormone-releasing hormone (GH-RH) that stimulates the pituitary gland to make more GH.
After a physical exam and a growth hormone level test and a growth hormone suppression test to confirm acromegaly, a CT scan and/or MRI will likely be performed to locate and assess the tumor. Surgery to remove a pituitary gland tumor is performed through the nose using an endoscopic surgical method.
Since tumors are usually found late-stage, removal alone is not usually successful in the suppression of GH. It takes a combination of treatments that include hormone blocking medication and radiation treatments to suppress and destroy remaining tumor cells. When left untreated, life expectancy of those with acromegaly can be greatly reduced.
No known prevention exists for acromegaly. However, early treatment can reduce the severity of symptoms and potentially avoid life-threatening complications. Initial treatment centers around lowering the production of GH as well as reducing the negative effect on the pituitary and nearby tissues.
Symptoms can be reduced or eliminated through surgical removal of a tumor, radiation or medication. Tumor removal can normalize GH production and eliminate the pressure on surrounding tissue. If part of the tumor remains, however, GH production will continue at higher levels, requiring additional treatment. Radiation may be recommended to eliminate the remnants of a tumor. Different medications offer options for reducing symptoms.