title: Congenital gigantism due to growth hormone-releasing hormone excess and pituitary hyperplasia with adenomatous transformation.
abstract: The cause of gigantism in most patients is a GH-secreting pituitary tumor. In this report, a case of congenital gigantism due to probable central hypersection of GH-releasing hormone (GHRH) is described. Normal at birth (4.4 kg; 53 cm), our 7-yr-old male patient grew progressively thereafter to attain a height of 182 cm and a weight of 99.4 kg at the time of our evaluation. The markedly increased baseline plasma levels of GH (730 micrograms/L) did not suppress during a standard 3-h oral glucose tolerance test, but did increase 54% after iv infusion of GHRH. Baseline plasma levels of insulin-like growth factor-I, PRL, and immunoreactive GHRH were also markedly increased. Computed imaging of the head showed a large, partially cystic sellar and suprasellar mass. Extensive imaging studies did not localize a potential source of GHRH. Preoperative treatment with octreotide and bromocriptine for 4 months resulted in a 25% reduction of suprasellar tissue mass. The pituitary tissue removed at transsphenoidal and transfrontal operations showed massive somatotroph, lactotroph, and mammosomatotroph hyperplasia. Areas of GH- and PRL-secreting cell adenomatous transformation were also evident. No histological or immunohistochemical evidence of a pituitary source of GHRH was found. The peripheral plasma immunoreactive GHRH concentration remained unaffected by pharmacological and surgical interventions. We suspect that a congenital hypothalamic regulatory defect may be responsible for the GHRH excess in this case.
authors.affiliation: Department of Pediatrics, Mayo Clinic, Rochester, Minnesota 55905.
authors.forename: D
authors.initials: D
authors.lastname: Zimmerman
authors.forename: W F
authors.initials: WF
authors.lastname: Young
authors.forename: M J
authors.initials: MJ
authors.lastname: Ebersold
authors.forename: B W
authors.initials: BW
authors.lastname: Scheithauer
authors.forename: K
authors.initials: K
authors.lastname: Kovacs
authors.forename: E
authors.initials: E
authors.lastname: Horvath
authors.forename: M D
authors.initials: MD
authors.lastname: Whitaker
authors.forename: N L
authors.initials: NL
authors.lastname: Eberhardt
authors.forename: T R
authors.initials: TR
authors.lastname: Downs
authors.forename: L A
authors.initials: LA
authors.lastname: Frohman
mesh_terms: D000236:Adenoma / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D001971:Bromocriptine / Q000627:therapeutic use; D002471:Cell Transformation, Neoplastic; D002648:Child; D005877:Gigantism / Q000151:congenital / Q000209:etiology*; D013006:Growth Hormone / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000378:metabolism*; D006801:Humans; D006965:Hyperplasia; D008279:Magnetic Resonance Imaging; D008297:Male; D015282:Octreotide / Q000627:therapeutic use; D010902:Pituitary Gland / Q000473:pathology*; D010911:Pituitary Neoplasms / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D011388:Prolactin / Q000378:metabolism*
chemical_list: D001971:Bromocriptine; D011388:Prolactin; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D015282:Octreotide