Gigantism

Gigantism refers to excessive growth both in height and specific body parts. Gigantism with extreme growth in height may be associated with disorders of the pituitary gland, which secretes human growth hormone (somatotrophin) during childhood before the bones fuse. Excessive growth of specific body parts is also a feature of a number of disorders such as the Beckwith-Wiedemann syndrome in which there is macroglossia (a large tongue due to overgrowth of the tongue).

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A condition of abnormal size or overgrowth of the entire body or of any of its parts. SYN: giantism. [G. gigas, giant]

- acromegalic g. a form of pituitary g. in which the signs of acromegaly accompany abnormal height.

- cerebral g. a syndrome characterized by increased birth weight and length (above 90th percentile), accelerated growth rate for the first 4 or 5 years without elevation of serum growth hormone levels, and then reversion to normal growth rate; characteristic facies include prognathism, hypertelorism, antimongoloid slant, and dolichocephalic skull; moderate mental retardation and impaired coordination are also associated. See Sotos syndrome.

- eunuchoid g. g. with deficient development of sexual organs; may be of pituitary or gonadal origin; g. accompanied by body proportions typical of hypogonadism during adolescence.

- fetal g. excessive fetal or newborn size, e.g., cerebral g. and infants of diabetic mothers.

- pituitary g. a form of g. caused by hypersecretion of pituitary growth hormone; a rare disorder commonly the result of a pituitary adenoma.

- primordial g. unusually large size from birth due to familial or genetic factors or intrauterine environment ( e.g., maternal prediabetic state) and not to hyperpituitarism.

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gi·gan·tism jī-'gan-.tiz-əm, jə-; 'jī-gən- n development to abnormally large size from excessive growth of the long bones accompanied by muscular weakness and sexual impotence and usu. caused by hyperpituitarism before normal ossification is complete called also macrosomia compare ACROMEGALY

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n.

abnormal growth causing excessive height, most commonly due to oversecretion during childhood of growth hormone (somatotrophin) by the pituitary gland. In eunuchoid gigantism the tall stature is due to delayed puberty, which results in continued growth of the long bones before their growing ends (epiphyses) fuse. See also acromegaly.

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gi·gan·tism (ji-ganґtiz-əm) (jiґgan-tiz-əm) [gigant- + -ism] abnormal overgrowth; excessive size and stature. Called also giantism, hypersomia, and somatomegaly.