Gigantism Associated with McCune-Albright's Syndrome

Abstract

The case of a 16 year-old boy with McCune-Albright's syndrome which is rarely accompanied by gigantism was studied endocrinologically. The stimulation of growth hormone (GH) release by hypoglycemia, the decline of elevated GH by hyperglycemia and a little lower somatostatin like immunoreactivity (SLI) may support abnormalities of hypothalamic function, but the existence of pituitary microadenoma cannot be ruled out because of the paradoxical suppression of GH release by oral administration of bromocriptine (CB-154) and L-DOPA and the stimulation of GH release by intravenous administration of TRH.

Acrodysplasia, severe ossification abnormalities with short stature, and fibular hypoplasia

“…Inactivating and activating mutations in the gene encoding G alpha s protein (GNAS1) have been shown to cause both skeletal abnormalities and alterations of GH secretory activity in Albright hereditary osteodystrophy (AHO) [Stirling et al, 1991] and in McCuneAlbright syndrome [Nakagawa et al, 1985]. Interestingly, marked shortness of the 4th and 5th metacarpals, a characteristic aspect of brachydactyly associated with AHO, was also found in our patient.…”

Bone Lesions

“…14,345,346 Diffuse thickening of the bones with involvement of the paranasal sinuses, orbits, and foramina of the skull base can produce a variety of symptoms, including headache, visual loss, proptosis, diplopia, hearing loss, anosmia, nasal obstruction, epistaxis, epiphora, mucocele, and sinusitis. Other hormonal abnormalities include acromegaly, 358 hyperprolactinemia, 359 hyperparathyroidism, 360 gynecomastia, 361 and Cushing's syndrome. 348,353 Biochemical abnormalities are rare in monostotic FD.…”

Multiple endocrine neoplasia: How many syndromes?

“…In one instance, the excess cortisol secretion was not suppressible by the high-dose dexamethasone regimen and an adrenal adenoma was removed [Benjamin and McRoberts, 19731; however, the other adrenal was noted to exhibit nodular hyperplasia at autopsy. The remaining patient with Cushing syndrome also had non-pigmented, nodular adrenal hyperplasia with undetectable serum ACTH levels [Danon et al, 19751. Gigantism or acromegaly has been in the McCuneAlbright syndrome on a number of occasions [Firat and Stutzman, 1968;Lightner et al, 1975;Polychronakos et al, 1982;Chung et al, 1983;Nakagawa et al, 1985;Cuttler et al, 19891. Because some patients exhibit associated hyperprolactinemia, and because of the oft-noted central sexual precocity, a hypothalamic basis for the endocrine hyperplasia has been entertained.…”