Health Information




Giantism; Pituitary giant

Gigantism is abnormal growth due to an excess of growth hormone during childhood.

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  • Causes

    The most common cause of too much growth hormone release is a noncancerous (benign) tumor of the pituitary gland. Other causes include:

    • Carney complex
    • McCune-Albright syndrome (MAS)
    • Multiple endocrine neoplasia type 1 (MEN-1)
    • Neurofibromatosis

    If excess growth hormone occurs after normal bone growth has stopped, the condition is known as acromegaly.

    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
    • Frontal bossing and a prominent jaw
    • Gaps between the teeth
    • Headache
    • 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
  • 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
    • Estradiol (girls)
    • Growth hormone suppression test
    • Prolactin
    • Increased growth factor-I
    • Testosterone (boys)
    • Thyroid hormone

    Imaging tests, such as CT or MRI scan of the head, also may be ordered to check for a pituitary tumor.

  • Treatment

    For pituitary tumors with well-defined borders, surgery can cure many cases.

    When surgery cannot completely remove the tumor, medicines are used to block or reduce growth hormone release.

  • Outlook (Prognosis)

    Pituitary surgery is usually successful in limiting growth hormone production.

    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:

    • Adrenal insufficiency
    • Diabetes insipidus (rarely)
    • Hypogonadism
    • Hypothyroidism
  • When to Contact a Medical Professional

    Call your health care provider if your child has signs of excessive growth.

Related Information

  Growth hormone tes...Long bonesTumorMultiple endocrine...McCune-Albright sy...Acromegaly    


Melmed S, Kleinberg D. Pituitary masses and tumors. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, Pa: Elsevier Saunders; 2011: chap 9.


Review Date: 11/7/2013  

Reviewed By: Brent Wisse, MD, Associate Professor of Medicine, Division of Metabolism, Endocrinology & Nutrition, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.

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