Acromegaly

Acromegaly is a hormonal disorder that develops when your pituitary gland produces too much growth hormone during adulthood. When this happens, your bones increase in size, including those of your hands, feet and face. Acromegaly usually affects middle-aged adults.

Acromegaly usually affects middle-aged adults, though it can develop at any age. In children who are still growing, too much growth hormone can cause a condition called gigantism. These children have exaggerated bone growth and an abnormal increase in height.

Because acromegaly is uncommon and physical changes occur gradually, the condition sometimes takes a long time to recognize. If it's not treated promptly, acromegaly can lead to serious illness and may even become life-threatening. But available treatments can reduce your risk of complications and significantly improve characteristics of the condition, including the enlargement of your features.

A common sign of acromegaly is enlarged hands and feet. People with this disorder often notice that they aren't able to put on rings that used to fit and that their shoe size has progressively increased.

Acromegaly may also cause gradual changes in the shape of your face, such as a protruding lower jaw and brow, an enlarged nose, thickened lips, and wider spacing between your teeth.

Because acromegaly tends to progress slowly, early signs may not be obvious for years. Sometimes, people notice the condition only by comparing old photographs with newer ones.

Acromegaly may produce the following signs and symptoms, which can vary from one person to another:

• Enlarged hands and feet
• Coarsened, enlarged facial features
• Coarse, oily, thickened skin
• Excessive sweating and body odor
• Small outgrowths of skin tissue (skin tags)
• Fatigue and muscle weakness
• A deepened, husky voice due to enlarged vocal cords and sinuses
• Severe snoring due to obstruction of the upper airway
• Impaired vision
• Headaches
• Enlarged tongue
• Pain and limited joint mobility
• Menstrual cycle irregularities in women
• Erectile dysfunction in men
• Enlarged organs, such as the heart
• Loss of interest in sex

When to see a doctor

If you have signs and symptoms associated with acromegaly, contact your doctor for an evaluation.

Acromegaly usually develops slowly. Even your family members may not initially notice the gradual physical changes that occur with this disorder, but early diagnosis is important so that you can start getting proper care. Acromegaly can lead to serious complications if it's not treated.

Acromegaly is caused by the pituitary gland overproducing growth hormone (GH) over time. The pituitary gland, a small gland situated at the base of your brain behind the bridge of your nose, produces a number of hormones. GH plays an important role in managing your physical growth.

When GH is secreted into your bloodstream, it triggers your liver to produce a hormone called insulin-like growth factor-I (IGF-I). In turn, IGF-I stimulates the growth of bones and other tissues.

If your pituitary gland makes too much GH, excessive amounts of IGF-I can result. Too much IGF-I can cause abnormal growth of your soft tissues and skeleton and other signs and symptoms characteristic of acromegaly and gigantism.

In adults, a tumor is the most common cause of too much GH production:

• Pituitary tumors. Most cases of acromegaly are caused by a noncancerous (benign) tumor (adenoma) of the pituitary gland. The tumor secretes excessive amounts of growth hormone, causing many of the signs and symptoms of acromegaly. Some of the symptoms of acromegaly, such as headaches and impaired vision, are due to the tumor mass pressing on nearby brain tissues.
• Nonpituitary tumors. In a few people with acromegaly, tumors in other parts of the body, such as the lungs or pancreas, cause the disorder. Sometimes, these tumors secrete GH. In other cases, the tumors produce a hormone called growth hormone-releasing hormone (GH-RH), which stimulates the pituitary gland to make more GH.

Treatment focuses on lowering your production of GH, as well as reducing the negative effects of the tumor on the pituitary gland and surrounding tissues. You may need more than one type of treatment.

Surgery

Doctors can remove most pituitary tumors using a method called transsphenoidal surgery. In this procedure, your surgeon works through your nose to extract the pituitary tumor.

Removing the tumor can normalize GH production and eliminate the pressure on the tissues surrounding your pituitary gland to relieve associated signs and symptoms. In some cases, your surgeon may not be able to remove the entire tumor. This may result in persistently elevated GH levels after surgery, requiring further medical or radiation treatments.

Medications

Drugs used to lower the production or block the action of GH include:

• Drugs that reduce excess growth hormone secretion (somatostatin analogues). The drugs octreotide (Sandostatin) and lanreotide (Somatuline Depot) are synthetic versions of the brain hormone somatostatin. They can interfere with the excessive secretion of GH by the pituitary gland, causing rapid declines in GH levels. These drugs are given by injection into the muscles of your buttocks (gluteal muscles) once a month by a health care professional.
• Drugs to lower hormone levels (dopamine agonists). The oral medications cabergoline and bromocriptine (Parlodel) lower levels of GH and IGF-I in some people. The tumor may decrease in size in some people taking a dopamine agonist. Some people may develop compulsive behaviors, such as gambling, while taking these medications.
• Drug to block the action of GH (growth hormone antagonist). The medication pegvisomant (Somavert) blocks the effect of GH on body tissues. Pegvisomant may be particularly helpful for people who haven't had good success with other forms of treatment. Given as a daily injection, this medication can normalize IGF-I levels and relieve symptoms in most people with acromegaly, but it doesn't lower GH levels or reduce the tumor size.

Radiation

Your doctor may recommend radiation treatment when tumor cells remain after surgery. Radiation therapy destroys any lingering tumor cells and slowly reduces GH levels. It may take years for this treatment to noticeably improve acromegaly symptoms.

Types of radiation therapy include:

• Conventional radiation therapy. This type of radiation therapy is usually given every weekday over a period of four to six weeks. You may not realize the full effect of conventional radiation therapy for 10 or more years after treatment.
• Proton beam therapy. Proton beam therapy delivers a targeted, high dose of radiation to the tumor, sparing radiation exposure to normal tissues. Proton beam therapy is provided in fractions over time, but treatment times are generally less than conventional radiation.
• Stereotactic radiosurgery. Stereotactic radiosurgery delivers a high dose of radiation to tumor cells in a single dose while limiting the amount of radiation to normal surrounding tissues. This type of radiation may bring GH levels back to normal within five years.

Even after initial treatment, acromegaly requires periodic monitoring by your doctor to make sure that your pituitary gland is functioning properly, which will help you avoid complications. This follow-up care may last for the rest of your life.