gigantism

gigantism /gi·gan·tism/ (ji-gan´tizm) (ji´gan-tizm) abnormal overgrowth; excessive size and stature.

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cerebral gigantism  gigantism in the absence of increased levels of growth hormone, attributed to a cerebral defect; infants are large, and accelerated growth continues for the first 4 or 5 years, the rate being normal thereafter. The hands and feet are large, the head large and dolichocephalic, the eyes have an antimongoloid slant, with hypertelorism. The child is clumsy, and mental retardation of varying degree is usually present.

pituitary gigantism  that caused by oversecretion of growth hormone by the pituitary gland.

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gi·gan·tism (j-gntzm)

n.

1. The quality or state of being gigantic; abnormally large size.

2. Excessive growth of the body or any of its parts, especially as a result of oversecretion of the growth hormone by the pituitary gland. Also called giantism.

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Gigantism

Excessive growth, especially in height, resulting from overproduction during childhood or adolescence of growth hormone by a pituitary tumor. Untreated, the tumor eventually destroys the pituitary gland, resulting in death during early adulthood. If the tumor develops after growth has stopped, the result is acromegaly, not gigantism.

Mentioned in: Growth Hormone Tests

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gigantism

[jigan′tizəm]

Etymology: L, gigas, giant

an abnormal condition characterized by excessive size and stature. It is caused most frequently by hypersecretion of growth hormone (GH) that occurs before the closure of the bone epiphyses; it occurs to a lesser degree in hypogonadism and in certain genetic disorders. Gigantism with normal body proportions and normal sexual development usually results from hypersecretion of GH in early childhood. Hypogonadism, by delaying puberty and closure of the epiphyses, may lead to gigantism. Excessive linear growth often occurs in males with more than one Y chromosome, and it may accompany Klinefelter's syndrome, Marfan's syndrome, and some cases of generalized lipodystrophy. Children with cerebral gigantism are mentally retarded and have a large head and extremities and a clumsy gait. Growth is rapid during their first few years and then reverts to a normal rate. Appropriate gonadal hormones may be administered to control abnormal growth of children with hypogonadism. The treatment of acromegalic gigantism is usually irradiation or surgical removal of the GH secreting adenoma. Compare acromegaly. See also eunuchoidism.

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gigantism [ji-gan´tizm, ji´gan-tizm]

abnormal overgrowth of the body or a part; excessive size and stature. Generally applied to a rare abnormality of the pituitary gland, which secretes excessive growth hormone before the growing ends of the bones have closed. This causes a child to become an unusually tall adult; if the abnormality is extreme, the individual may reach a height of 2.4 meters (8 feet) or more, although the body proportions usually are normal.

The opposite condition, dwarfism, is caused by underproduction of the same hormone. (Overproduction of growth hormone in adults causes acromegaly.) Gigantism can be corrected only by early diagnosis in childhood and removal by surgery of part of the pituitary gland or by x-ray treatment.

cerebral gigantism gigantism in the absence of increased levels of growth hormone, attributed to a cerebral defect; infants are large, and accelerated growth continues for the first 4 or 5 years, the rate being normal thereafter. The hands and feet are large, the head is large, narrow and long, and the eyes have an antimongoloid slant with an abnormally wide space between them. The child is clumsy, and mental retardation of varying degree is usually present. Called also Sotos syndrome.

pituitary gigantism that caused by oversecretion of growth hormone by the pituitary gland; see gigantism. Called also Launois syndrome.

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gigantism

abnormal overgrowth of the body or a part; excessive size and stature. The condition results from overproduction of growth hormone before the epiphyseal plates have closed. The opposite condition, dwarfism, is caused by underproduction of the same hormone. Overproduction of growth hormone in adults causes acromegaly.