SUN-028 - Gigantism and Acromegaly in 20Yo Female with 5.5 Cm Pituitary Adenoma

Intro:
Acromegaly is rare (0.2-1.1 annual cases per 100,000) and is associated with substantial comorbidities, including cardiovascular disease and neoplasms. Diagnostic delay averages 4.5-5.5 years, due to insidious onset and physician unfamiliarity with the condition. Thus, most are detected as macroadenomas, with higher risk of recurrence, especially in cases of cavernous sinus invasion. We present a case of gigantism and acromegaly in a young adult female.

Case:
A 20-year-old presented with acute headache, vomiting, excessive thirst, right-sided ophthalmoplegia and pupillary defect. Imaging showed a large pituitary mass (5.1 x 5.2 x 5.5 cm) with cavernous sinus extension and pituitary apoplexy. Physical exam showed tall stature of 74” (midparental height of 65”), acral enlargement, coarse facial features, prognathism and acanthosis nigricans. Past medical history of secondary amenorrhea for 3 years. Labs on presentation showed hypernatremia, elevated IGF-1 of 729 ng/mL, prolactin 59 ng/mL, Hgb A1c 8.1% and low estradiol < 20 pg/mL. She underwent endoscopic transsphenoidal pituitary resection, with benign pathology, positive GH and prolactin staining. The post-operative course included management of hypopituitarism with desmopressin, levothyroxine and hydrocortisone, and management of secondary diabetes mellitus. At 3 months postop, patient has midnormal IGF-1 with deficiency in other pituitary axes, diet-controlled diabetes, recovery of third nerve palsy and imaging with minimal residual tumor vs scarring in the lateral cavernous sinus.

Discussion:
This case exemplifies the diagnostic delay encountered in acromegaly, despite key physical exam findings and comorbid conditions. Notably, 20 months prior, she reported to primary care with 1 year of amenorrhea, polyuria and polydipsia. The lab evaluation at the time included TSH, LH, FSH, ACTH, cortisol, aldosterone, free and total testosterone, all within normal limits, while prolactin, estrogen and IGF-1 were not assessed.
The marked discrepancy in the patient’s stature compared to the midparental height reflects a combined presentation of gigantism and acromegaly, indicating presence of elevated GH levels prior to fusion of growth plates. This patient’s giant adenoma is highly specific for hypopituitarism, invasiveness, and risk for recurrence. Along with surveillance for recurrence, our patient is monitored for systemic complications including malignancy screening with colonoscopy, DEXA scan, cardiovascular screening for hypertension, and echocardiography.
Menstrual disorders are a frequent early presenting symptom in pituitary adenomas. When associated with specific physical exam findings and comorbid conditions, caring physicians should consider a potential secreting adenoma and refer to Endocrinology for comprehensive evaluation of pituitary axes.

*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.*