SAT-227 - When Tall Stature Hides A Tumor: A Case of Pituitary Gigantism in Childhood

Background: Pituitary gigantism is a very rare condition resulting from excessive secretion of growth hormone (GH), usually by a pituitary adenoma. Although the clinical focus is on excessive height in the first instance, the pathological effects of excess levels of GH and insulin-like growth factor-1 (IGF1) are systemic and involve multiple organs. Early diagnosis and rapid referral for effective therapy improve outcomes in these patients.

Clinical case: A 12 year-old boy was referred because of tall stature. His parents reported that his height velocity (HV) had accelerated from age 7 years and he had been exhibiting acral enlargement since last year. At initial assessment his weight was 109,2 kg (+4,6 SD) and height was 187,5 cm (+5,4 SD), 4 SD above his mid-parental height.
He was Tanner stage 3 for genitalia, Tanner stage 4 for pubic hair and his testicular volumes measured 15 ml. He had no headaches or visual disturbances. Laboratory tests showed increased levels of IGF1 (1501 ng/ml (3,4 upper limit normal (ULN)) and hyperprolactinemia (32,5 ng/ml). The remaining pituitary profile (thyroid function test, cortisol, LH, FSH and testosterone) and visual fields were normal. MRI detected an adenohypophyseal lesion suggestive of a macroadenoma, measuring 10 x 12 x 9 mm without signs of cavernous sinus invasion, suprasellar extension or optic chiasm compression. Bone age was coincident with his chronological age. He underwent transsphenoidal surgery. Histology confirmed a pituitary adenoma which was positive for growth hormone and prolactin. One month post-surgery IGF1 declined to 403 ng/ml (0,92 ULN). He did not develop any other pituitary hormone deficiencies. At the moment, the 3-month follow-up was not performed.
Despite the delay in diagnosis ( 5 years) and marked increase of IGF1, the patient did not present with comorbidities associated with GH excess.

Conclusions: We report a case of pituitary gigantism that was surgically intervened in and is still under follow-up.
Treating these patients remains challenging. Pituitary gigantism is a rare disease that can be difficult to manage, requiring in some cases a combination of therapeutic strategies.

*Unless otherwise noted, all abstracts presented at ENDO must not be released to the press or the public until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.*