Gigantism
Gigantism; Pituitary giant; Overproduction of growth hormone; Growth hormone - excess production
Gigantism is abnormal growth due to an excess of growth hormone during childhood.
Growth hormone
The growth hormone test measures the amount of growth hormone in the blood. The pituitary gland makes growth hormone, which causes a child to grow. ...
Causes
The most common cause of too much growth hormone release is a noncancerous (benign) tumor of the pituitary gland. Other causes include:
Tumor
A tumor is an abnormal growth of body tissue. Tumors can be cancerous (malignant) or noncancerous (benign).
- Genetic disease that affects the skin color (pigmentation) and causes benign tumors of the skin, heart, and endocrine (hormone) system (Carney complex)
-
Genetic disease that affects the bones and skin pigmentation (
McCune-Albright syndrome
)
McCune-Albright syndrome
McCune-Albright syndrome is a genetic disease that affects the bones and color (pigmentation) of the skin.
-
Genetic disease in which one or more of the endocrine glands are overactive or form a tumor (
Multiple endocrine neoplasia type 1
)
Multiple endocrine neoplasia type 1
Multiple endocrine neoplasia (MEN) type I is a disease in which one or more of the endocrine glands are overactive or forms a tumor. It is passed do...
- Disease in which tumors form on the nerves of the brain and spine (neurofibromatosis)
If excess growth hormone occurs after normal bone growth has stopped, the condition is known as acromegaly .
Acromegaly
Acromegaly is a condition in which there is too much growth hormone in the body.
Gigantism is very rare.
Symptoms
The child will grow in height, as well as in the muscles and organs. This excessive growth makes the child extremely large for his or her age.
Other symptoms include:
- Delayed puberty
- Double vision or difficulty with side (peripheral) vision
-
Very prominent forehead (
frontal bossing
) and a prominent jaw
Frontal bossing
Frontal bossing is an unusually prominent forehead. It is sometimes associated with a heavier than normal brow ridge.
- Gaps between the teeth
-
Headache
Headache
A headache is pain or discomfort in the head, scalp, or neck. Serious causes of headaches are rare. Most people with headaches can feel much better...
- Increased sweating
- Irregular periods (menstruation)
- Large hands and feet with thick fingers and toes
- Release of breast milk
- Sleep problems
- Thickening of the facial features
- Weakness
- Voice changes
Exams and Tests
The doctor will perform a physical exam and ask about the child's symptoms.
Laboratory tests that may be ordered include:
-
Cortisol
Cortisol
The cortisol blood test measures the level of cortisol in the blood. Cortisol is a steroid (glucocorticoid) hormone produced by the adrenal gland. C...
-
Estradiol
(girls)
Estradiol
An estradiol test measures the amount of a hormone called estradiol in the blood.
-
Growth hormone suppression test
Growth hormone suppression test
The growth hormone suppression test determines whether growth hormone production is being suppressed by high blood sugar.
-
Prolactin
Prolactin
Prolactin is a hormone released by the pituitary gland. The prolactin test measures the amount of prolactin in the blood.
- Insulin-like growth factor-I
-
Testosterone
(boys)
Testosterone
DHEA stands for dehydroepiandrosterone. It is a weak male hormone (androgen) produced by the adrenal glands in both men and women. The DHEA-sulfate...
- Thyroid hormone
Imaging tests, such as CT or MRI scan of the head, also may be ordered to check for a pituitary tumor .
CT
A head computed tomography (CT) scan uses many x-rays to create pictures of the head, including the skull, brain, eye sockets, and sinuses.
MRI
A magnetic resonance imaging (MRI) scan is an imaging test that uses powerful magnets and radio waves to create pictures of the body. It does not us...
Pituitary tumor
A pituitary tumor is an abnormal growth in the pituitary gland. The pituitary is a small gland at the base of the brain. It regulates the body's ba...
Treatment
For pituitary tumors that have clear outlines, surgery can cure many cases.
When surgery cannot completely remove the tumor, medicines are used to block or reduce growth hormone release or prevent growth hormone from reaching target tissues.
Sometimes radiation treatment is used to decrease the size of the tumor after surgery.
Outlook (Prognosis)
Pituitary surgery is usually successful in limiting growth hormone production.
Growth hormone
The growth hormone test measures the amount of growth hormone in the blood. The pituitary gland makes growth hormone, which causes a child to grow. ...
Early treatment can reverse many of the changes caused by growth hormone excess.
Possible Complications
Surgery may lead to low levels of other pituitary hormones, which can cause any of the following conditions:
- Adrenal insufficiency (adrenal glands do not produce enough of their hormones)
-
Diabetes insipidus
(extreme thirst and excessive urination; in rare cases)
Diabetes insipidus
Diabetes insipidus is an uncommon condition in which the kidneys are unable to prevent the excretion of water.
-
Hypogonadism
(body's sex glands produce little or no hormones)
Hypogonadism
Hypogonadism occurs when the body's sex glands produce little or no hormones. In men, these glands (gonads) are the testes. In women, these glands ...
-
Hypothyroidism
(thyroid gland does not make enough thyroid hormone)
Hypothyroidism
Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone. This condition is often called underactive thyroid....
When to Contact a Medical Professional
Call your health care provider if your child has signs of excessive growth.
References
Katznelson L, Laws ER Jr, Melmed S, et al. Acromegaly: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab . 2014;99:3933-51. PMID: 25356808 www.ncbi.nlm.nih.gov/pubmed/25356808 .
Melmed S. Acromegaly. In: Jameson JL, De Groot LJ, de Kretser DM, et al, eds. Endocrinology: Adult and Pediatric . 7th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 12.
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Endocrine glands - illustration
Endocrine glands release hormones (chemical messengers) into the bloodstream to be transported to various organs and tissues throughout the body. For instance, the pancreas secretes insulin, which allows the body to regulate levels of sugar in the blood. The thyroid gets instructions from the pituitary to secrete hormones which determine the pace of chemical activity in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).
Endocrine glands
illustration
-
Endocrine glands - illustration
Endocrine glands release hormones (chemical messengers) into the bloodstream to be transported to various organs and tissues throughout the body. For instance, the pancreas secretes insulin, which allows the body to regulate levels of sugar in the blood. The thyroid gets instructions from the pituitary to secrete hormones which determine the pace of chemical activity in the body (the more hormone in the bloodstream, the faster the chemical activity; the less hormone, the slower the activity).
Endocrine glands
illustration
Review Date: 10/28/2015
Reviewed By: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.