Multiple: Gigantism

Definition
Description
Demographics
Causes and Symptoms
Diagnosis
Treatment
Prognosis
Prevention
The Future
For more information

Definition

Gigantism is a term for abnormal growth in height in children caused by too much growth hormone. An oversupply of growth hormone in adults who have completed their skeletal growth leads to a condition called acromegaly.

Gigantism in children and adolescents is based on a comparison of the child's height and weight to those of others of his or her age, sex, and level of sexual maturity; there is no absolute minimum height or weight that defines gigantism.

Description

Gigantism in children can begin at any age before the growth plates in the long bones of the body close, usually by the early twenties. It is often quite dramatic because parents typically notice their children's growth and because the growth plates in the arms and legs respond quickly to growth hormone. The tallest man ever recorded, Robert Wadlow (1918–1940) of Alton, Illinois, began growing abnormally rapidly at the age of four. By age 10 he was 6 feet 6 inches tall (2 meters); by age 16 he was 7 feet 11 inches tall (2.4 meters); at the time of his death at age 22 he was 8 feet 11 inches (2.7 meters) tall and reportedly still growing.

Acromegaly in adults, by contrast, is much slower in onset, is not recognized as quickly, and may continue for some years before it is diagnosed. Most adults with acromegaly begin to develop symptoms in their twenties but diagnosis is delayed on average for about nine years, with some patients not diagnosed for fifteen years. The average age at diagnosis is forty years.

Demographics

Both gigantism and acromegaly are rare disorders, although gigantism is much rarer than acromegaly. There are only about a hundred known cases of gigantism reported in medical journals, whereas acromegaly affects between forty and seventy adults per 1 million population.

As far as is known, males and females are equally affected by gigantism and acromegaly, as are members of all races and ethnic groups.

Causes and Symptoms

Gigantism in children is caused by too much growth hormone produced by the pituitary gland, which is a peanut-shaped gland that lies at the base of the brain behind the nose. There are several reasons why this gland may start overproducing. The most common cause is a benign (noncancerous) tumor in the pituitary gland that leads to the secretion of too much hormone. The second reason, which is much less common, is one of several

rare medical conditions that also affect the pituitary gland. The third cause, which is very rare, is that the child has an oversupply of a protein that increases the activity of a normal supply of growth hormone.

Acromegaly in adults is caused by a tumor in the pituitary gland leading to an oversupply of growth hormone in 95 percent of cases; however, there are also cases of acromegaly caused by tumors in the pancreas, adrenal glands, or lungs. These tumors may actually secrete growth hormone, or they may secrete another hormone that stimulates the pituitary gland to produce more growth hormone.

André the Giant (1946–1993)

André the Giant was the stage name of a professional wrestler and movie actor named André Roussimoff. He was born in Coulommiers, France, to parents of Bulgarian and Polish descent. He quit school after eighth grade and worked as a farm laborer and factory worker for several years. He was then discovered by a wrestling promoter and moved to Paris to train as a professional wrestler. By the time he was 21, he had become a European wrestling star. He traveled to Japan for a wrestling match in 1969; at that time he was diagnosed by a Japanese doctor as having acromegaly.

In 1973 André began his wrestling career in North America and took the stage name of “André the Giant.” He became an actor as a sideline to wrestling. He starred in several films and television series in the 1970s and 1980s, including the role of Fezzik in The Princess Bride, which was his favorite part. By 1987, however, André's weight had reached 560 pounds, and his bones and joints were causing him great pain. Although he continued to wrestle professionally until 1991, his health gradually failed. He died in his sleep in

January 1993 of congestive heart failure after returning to Paris to attend his father's funeral. His death was attributed to the acromegaly.

The symptoms of gigantism and acromegaly include the following:

• Rapid increase in height (in children)
• Increase in weight leading to mild or moderate obesity

• Headaches and vision problems caused by the pressure of a pituitary tumor on the optic nerve and other parts of the brain
• Exaggeratedly large hands and feet with unusually thick fingers and toes
• Coarse facial features with an enlarged jaw and rounded swelling of the forehead
• Thick, oily skin with heavy sweating and body odor
• Deepened or husky voice, tendency to snore heavily at night
• Joint problems leading eventually to osteoarthritis
• Increased risk of other benign tumors and diabetes
• Delayed puberty in children; sexual problems in adults
• Enlarged liver, heart, spleen, and kidneys
• Overgrowth of soft tissue

Diagnosis

The diagnosis of gigantism or acromegaly is made on the basis of the patient's history and a series of laboratory tests and imaging studies. The most common is a blood test taken after the patient has fasted overnight, which evaluates the level of growth hormone and another hormone secreted by the liver in response to growth hormone. If the levels of both hormones are high, the test indicates gigantism or acromegaly.

A second blood test that may be performed to confirm the diagnosis is called a growth hormone suppression test. The patient has two blood samples taken, one before and one after drinking a sugar solution. In a normal person, the level of growth hormone will drop after drinking the sugar solution. If the level stays high, it confirms a diagnosis of gigantism or acromegaly.

The doctor will also usually order a CT scan or MRI in order to determine whether there is a tumor in the patient's pituitary, or whether a tumor elsewhere in the body may be responsible for the high levels of growth hormone. In a few cases the patient may also need a chest x-ray to help locate the tumor.

Treatment

The most common treatment for gigantism and acromegaly is surgical removal of the pituitary tumor. This is a complicated procedure requiring a highly experienced surgeon. In some cases the surgeon cannot remove the entire tumor. The patient is then treated with synthetic

hormones that block the production of growth hormone, or with a newer drug that blocks the effect of growth hormone on body tissues. The patient must inject these drugs at home on a daily basis.

Patients whose tumor cannot be completely removed by surgery may be given radiation therapy. This type of treatment is considered a last resort, however, as it usually upsets the balance of other hormones in the body and can cause learning difficulties, obesity, and personality changes in children. In addition, radiation therapy may take from eighteen months to several years to stop the overproduction of growth hormone and requires frequent follow-up treatments for the rest of the patient's life.

Prognosis

The prognosis for patients with gigantism or acromegaly is usually good to excellent following surgery; smaller tumors can be removed successfully about 85 percent of the time and larger tumors between 50 and 65 percent of the time. About 13 percent of children with pituitary tumors have a recurrence of the tumor after surgery, however.

With regard to medications, some patients do not respond to the drugs that are currently used. Radiation therapy can cause complications by suppressing the secretion of other body hormones as well as fighting the cells in a pituitary tumor. About 60 percent of patients who are treated with radiation therapy for acromegaly must take hormone replacements for the rest of their lives.

Although gigantism and acromegaly are not fatal by themselves, they can cut short a patient's life span if they are not treated because of the extra strain put on the lungs and heart by the patient's body size. Patients with untreated acromegaly usually develop high blood pressure (hyper-tension) and heart problems. They are also at increased risk of diabetes, breast or colon cancer, osteoarthritis, vision loss, carpal tunnel syndrome, spinal cord compression, and uterine polyps (in women).

Prevention

There is no known way to prevent gigantism or acromegaly because the factors that lead to pituitary tumors are not well understood. It is known that gigantism and acromegaly are not hereditary, because patients with these conditions typically have parents and siblings of normal height and weight.

The Future

Gigantism and acromegaly are both rare disorders and not likely to increase in frequency over the next few decades. It may be that improved surgical techniques or the development of new medications will make it easier to treat these conditions without the side effects that many patients presently have to accept. Two newer drugs were at the clinical trial stage as of early 2008.

SEE ALSO Childhood obesity; Diabetes; Heart failure; Hypertension; Osteoarthritis

WORDS TO KNOW

Acromegaly: A condition in which a person 's body produces too much growth hormone in adult life.

Gigantism: Excessive production of growth hormone in children who are still growing.

Growth plate: A cartilage plate in the long bones of children where the lengthening of bone takes place.

Pituitary gland: A pea-sized gland located at the base of the brain behind the nose that secretes growth hormone and other hormones that affect sexual development and the body 's response to stress.

For more information

BOOKS

Brannan, Dan. Boy Giant: The Story of Robert Wadlow, the World 's Tallest Man. Alton, IL: Alton Museum of History and Art, 2003.

Davies, Ross. Andre the Giant. New York: Rosen Publishing Group, 2001.

WEB SITES

André the Giant. Biography. Available online at http://www.andrethegiant.com/bio.html (accessed April 24, 2008).

Mayo Clinic. Acromegaly. Available online at http://www.mayoclinic.com/health/acromegaly/DS00478/DSECTION=1 [accessed April 24, 2008].

National Institute of Neurological Disorders and Stroke (NINDS). Pituitary Tumors Information Page. Available online at http://www.ninds.nih.gov/disorders/pituitary_tumors/pituitary_tumors.htm (accessed April 24, 2008).

World 's Tallest Man. Video of Robert Wadlow. Available online at http://www.maniacworld.com/worlds_tallest_man.htm (accessed April 24, 2008) Video runs about five minutes; voiceover is in English but has Finnish subtitles.