Gigantism is abnormal growth due to an excess of growth hormone (GH) during childhood.
Pituitary giant; Overproduction of growth hormone; Growth hormone - excess production
Gigantism is very rare. The most common cause of too much GH release is a noncancerous (benign) tumor of the pituitary gland. Other causes include:
If excess GH occurs after normal bone growth has stopped (end of puberty), the condition is known as acromegaly.
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:
Exams and Tests
The health care provider will perform a physical exam and ask about the child's symptoms.
Laboratory tests that may be ordered include:
For pituitary tumors, surgery can cure many cases.
When surgery cannot completely remove the tumor, medicines are used to block or reduce GH release or prevent GH from reaching target tissues.
Sometimes radiation treatment is used to decrease the size of the tumor after surgery.
Pituitary surgery is usually successful in limiting GH production.
Early treatment can reverse many of the changes caused by GH excess.
Surgery and radiation treatment may lead to low levels of other pituitary hormones. This can cause any of the following conditions:
When to Contact a Medical Professional
Call your provider if your child has signs of excessive growth.
Gigantism cannot be prevented. Early treatment may prevent the disease from getting worse and help avoid complications.
Katznelson L, Laws ER Jr, Melmed S, et al; Endocrine Society. Acromegaly: an endocrine society clinical practice guideline. J Clin Endocrinol Metab. 2014;99(11):3933-3951. 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.
Review Date: 5/6/2019
Reviewed By: Brent Wisse, MD, board certified in Metabolism/Endocrinology, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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