Gigantism
Gigantism is a rare condition primarily caused by tumors in the pituitary gland, which lead to an overproduction of growth hormone. This excess hormone stimulates abnormal growth in children and adolescents, resulting in significantly larger body size and height—often exceeding 6 feet, 6 inches. The condition is characterized by rapid growth, with children potentially growing up to six inches per year. If left untreated, gigantism can lead to various health complications, including mental health issues, sexual immaturity, and a reduced life expectancy due to the musculoskeletal system's inability to support such height.
When growth hormone levels are high after bone growth has completed, the condition shifts to acromegaly, which affects adults and causes thickening of bones and enlargement of facial features. Diagnosis typically involves blood tests and imaging scans to assess hormone levels and identify tumors. Treatment options include surgery, medication, and, in some cases, radiation therapy, although reversing existing health issues from the condition is not possible. Ongoing research aims to understand genetic factors that may predispose individuals to pituitary tumors, shedding light on both historical and contemporary figures known for their gigantism.
Gigantism
Also known as: Giantism, acromegaly, somatotroph adenoma, growth hormone excess, pituitary giant
Anatomy or system affected: Arms, bones, brain, circulatory system, endocrine system, eyes, hair, hands, legs, musculoskeletal system, reproductive system
Definition: Gigantism is a rare disease that begins in children with pituitary gland tumors that overproduce growth hormone, resulting in excessive stature and hormonal imbalances. After adolescence, the disease manifests as acromegaly, which is quite serious over the long term.
Causes: Endocrine disorder resulting in pituitary gland tumors
Symptoms: Enlargement of bones of hands, feet, and face; excessive growth and height; sometimes mental illness; sexual immaturity; difficulty walking and standing
Duration: Lifelong
Treatments: Chemotherapy, antigrowth hormone drugs, surgery, radiation therapy
Causes and Symptoms
Gigantism is a rare disease most often caused by the presence of tumors of the peanut-sized pituitary gland , located at the base of the brain. Such tumors produce an excess of growth hormone, the biomolecule responsible for overall growth. In children or adolescents who have these tumors, excess growth hormone results in overgrowth of all parts of the body. Gigantism occurs because the bones of the arms and legs have not yet calcified and can grow much longer than usual. Hence, an afflicted child becomes very large in size and very tall, often reaching a height of more than 6 feet, 6 inches.
A young child afflicted with pituitary gigantism grows in height as much as six inches per year. Thus, an important symptom that identifies the problem is that such children are much taller and larger than others of the same age. In many cases, this great size difference may lead to individuals who are more than twice the height of their playmates. Excessive growth of this sort should lead parents to seek the immediate advice of their family physician, who can aid in the selection of a specialist to identify the problem and develop an appropriate treatment.
As gigantism proceeds, pituitary tumors often invade and replace the rest of the pituitary gland. This is unfortunate, because the pituitary gland produces several other hormones —called "trophic hormones"—that control mental processes, sexual maturation, and healthy overall growth. Consequently, prolonged, untreated gigantism may yield a huge individual who suffers from mental illness, is sexually immature, and becomes quite unhealthy. In addition, the human musculoskeletal system is not designed to accommodate individuals attaining the great heights of many postadolescent pituitary giants. Hence, it is fairly common that affected individuals have great difficulty standing and walking; some can do so only with the aid of canes. Moreover, the average life expectancy of an individual with untreated gigantism or acromegaly is shorter than that of individuals of normal stature.
In cases where pituitary tumors that oversecrete growth hormone occur after calcification of the long bones is complete—after adolescence—gigantism will not occur. Such individuals develop acromegaly. This often-fatal disease, progressive throughout life, thickens bones and causes the overgrowth of all body organs. Hands and feet grow larger, and the lower jaw, brow ridges, nose, and ears enlarge, coarsening the features. More damaging is the development of headaches, high blood pressure, high cholesterol levels, arthritis, type 2 diabetes, sleep apnea, and even colon cancer over the long run. It should be noted that these disabilities are rarely seen in pediatric patients and most often begin in the third or fourth decade of life. Many medical scientists believe that pituitary gigantism and acromegaly are the basis for the legends about giants and ogres.
Treatment and Therapy
If a diagnosis of gigantism or acromegaly seems probable, the physician or specialist involved will order a blood test to identify the amount of growth hormone present in the body. Computed tomography (CT) and magnetic resonance imaging (MRI) scans will also be carried out, especially in those suspected of having acromegaly, to identify possible organ changes away from normal size.
In cases where growth hormone levels are high and cannot be reduced by chemotherapy—for example, with antigrowth hormone drugs such as somatostatin analogs, dopamine agonists, and growth hormone receptor antagonists—and/or the presence of a clearly defined tumor is identified via CT and MRI, surgery to excise the tumor will be attempted. Radiation therapy is associated with a number of detrimental effects and with a slower response time; thus, chemotherapeutic and surgical interventions are preferred over radiation in most cases.
Perspective and Prospects
It must be recognized that the success of any therapeutic regimens or their combination will prevent additional gigantism or symptoms of acromegaly from occurring. It is not possible, however, to reverse existing consequences of the pituitary tumors on young children and adolescents with gigantism or on adults with acromegaly.
For this reason, it is essential for worried parents or adult patients to visit an appropriate physician as quickly as possible. Such foresight will usually minimize problems associated with either manifestation of pituitary tumors and enable an afflicted individual to have the best possible future life. In addition to extirpating causative tumors, it will then become possible, after additional blood tests and the thorough examination of CT and MRI data, to identify which body organs need to be treated and to arrest or minimize health complications, such as those associated with the reproductive, cardiovascular, and musculoskeletal systems.
In an effort to determine whether there is a gene mutation that can make individuals more susceptible to the development of pituitary tumors, researchers have been studying certain relevant genes in the hopes of discovering a link that would enable them to detect the disease in carriers earlier. In 2011, a team of scientists in England and Germany studied the DNA from the skeleton of Charles Byrne, an eighteenth-century man who had been famous due to his gigantism, and discovered that he had had a rare gene mutation believed to be inherited.
Gigantism in Popular Culture
While the disease is known to be life shortening and often painful, some individuals have become widely known for their gigantism through research and entertainment. In Hollywood, actors with gigantism who had memorable roles have included André René Roussimoff, known as André the Giant (particularly for his roles as a wrestler and as Fezzik in the 1987 classic The Princess Bride) and Richard Kiel, who played the villain Jaws in films for the James Bond franchise.
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