• Definition

    Gigantism is abnormally large growth due to an excess of growth hormone during childhood, before the bone growth plates have closed.

    Alternative Names


    Causes, incidence, and risk factors

    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.