Gigantism caused by excessive GH secretion usually
because of a pituitary adenoma that normally occurs before the epiphyses are
fused in comparison with acromegaly that occurs after fusion of the
Acromegaloid Gigantism; Fractional Hypopituitarism-Gigantism Syndrome; Neurath-Cushing Syndrome; Pituitary Gigantism;
Very rare cause of tall stature in children. Reports are
limited to sporadic cases. Peak incidence in teenagers, although it has been
reported in a child as young as 21 months.
Almost always caused by pituitary adenoma,
producing excessive GH. Some tumors are mixed and produce both prolactin and
GH. Very rarely it is caused by excessive secretion of GH-releasing factor
from an ectopic source.
Rapid linear growth, tall stature, large hands
and feet, coarsening of facial features, prognathism, macroglossia, widely
spaced teeth, and husky voice. Other features include greasy thick skin, slipped epiphyses with joint
pain, kyphoscoliosis, myopathy, nerve entrapment syndromes; headaches and
visual field defects, usually hemianopsia, pale optic discs and optic
atrophy. Patients may have behavioral problems and mental retardation, early pubertal
signs, galactorrhea, glucose intolerance, obesity, or diabetes mellitus.
Clinical features; biochemical (elevated serum levels of
GHs not suppressed by oral glucose loading, elevated levels of IGF-1, high
prolactin and gonadotropin levels); radiology (advanced bone age, enlarged
sella turcica on skull radiograph, CT scan demonstrates pituitary tumor).
May be anxious and uncooperative in the
presence of visual defects, mental retardation, or behavioral problems.
Airway problems should be anticipated, but, unlike acromegaly, glottic
stenosis and vocal cord paresis have not been reported in gigantism.
Presence of myopathy may predispose to postoperative respiratory
insufficiency. Close monitoring of preoperative glucose level necessary in
the presence of diabetes mellitus. If the patient is already being treated,
complications of medical and/or irradiation therapy, such as pituitary
insufficiency, should be evaluated preoperatively.
Acromegaly: Hormonal disorder caused by overproduction of GH in
adults, not resulting in gigantism but enlargement of extremities, usually a
result of a benign tumor of the pituitary gland.
Alvi NS, Kirk JM: Pituitary gigantism causing diabetic ketoacidosis. J Pediatr Endocrinol
Daughaday WH: Pituitary gigantism. Endocrinol Metab Clin North Am
Lu PW, Silink M, Johnston I, et al: Pituitary gigantism. Arch Dis Child