Introduction: Gigantism and acromegaly are rare syndromes characterized by excessive growth hormone (GH) secretion, most commonly caused by a pituitary tumor. Pediatric somatotropinomas tend to be atypical, larger, and more aggressive, which leads to diagnostic and therapeutic challenges in this population. Case Description: Case 1: A 16-year-old female presented for evaluation of primary amenorrhea. Her mother reported rapid growth after age 9 and pubertal onset at age 12 with a progression but lack of menstrual cycles. She denied headaches or vision changes. On exam, she was at the 95th percentile for height with a genetic target at the 50th percentile. Initial evaluation including serum prolactin, luteinizing hormone (LH), testosterone, and thyroid function tests (TFTs) were normal. Insulin like growth factor-1 (IGF-1) was elevated at 1162 ng/mL (147-646). GH suppression test was abnormal; GH nadir was 4.1 at 30 minutes after a 75-gram load of glucose (<1 ng/ml). MRI of the pituitary revealed a 1.9 x 1.3 x 1.3 cm lobular mass within the sella and suprasellar region, with displacement of the pituitary stalk and optic chiasm (Figure 1). She successfully underwent transsphenoidal resection of the pituitary mass. Postoperatively, she presented with transient diabetes insipidus (DI). She developed secondary hypothyroidism and hypogonadism. Four days post-operatively, her IGF-1 started declining and then normalized at 2 months. Case 2: A 15-year-old girl presented for evaluation of irregular menses. On exam, she had coarse facial features, large hands and feet, acanthosis nigricans, hirsutism, and a deep voice. Height was at the 50th percentile (genetic target 25th percentile). Initial evaluation revealed very elevated serum prolactin of 260 ng/dL. Serum LH was low at 0.14 mIU/mL (0.97-14.7). Further evaluation revealed an elevated IGF-I level at 1374 ng/mL (208-619), elevated IGF binding protein-3 (IGFBP-3) of 11.2 mg/L (3.4-9.5) with normal cortisol and serum sodium. She had mixed hyperlipidemia. TFTs were normal. GH suppression test confirmed excessive GH production (GH nadir 11.7 ng/mL at 120 minutes) and MRI revealed a pituitary macroadenoma measuring 1.7 x 1.5 x 2 cm invading the cavernous sinus and wrapping around the internal carotid artery (Figure 2). She underwent partial transsphenoidal resection of the pituitary mass. She was briefly treated with pegvisomant and underwent a second surgical resection for persistent disease. Discussion: The incidence of acromegaly is 3 to 4 per 1 million per year in children. The existing literature is limited to isolated case reports from adults. Additionally, the insidious nature of acromegaly and atypical symptoms causes many cases to be overlooked and consequently, delay the diagnosis. Conclusion: Pituitary adenoma presenting as acromegaly is rare in children and may present with unusual symptoms of other pituitary hormone dysfunction, like in our patients. Physicians need to consider evaluation for gigantism/acromegaly in children with pituitary tumors and abnormal growth findings.

Figure 1

Sagittal T1 weighted image showing a 1.9 x 1.3 x 1.3cm lobular mass centered in the sella and suprasellar region (left). Axial T1 image showing the mass (right).

Figure 1

Sagittal T1 weighted image showing a 1.9 x 1.3 x 1.3cm lobular mass centered in the sella and suprasellar region (left). Axial T1 image showing the mass (right).

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Figure 2

Sagittal T1 image showing a 1.7 x 1.5 x 2cm pituitary macroadenoma. Pituitary stalk and remaining pituitary gland are deviated to the right (left). T1 coronal image showing the same macroadenoma invading into the cavernous sinus and wrapping around the ICA (right).

Figure 2

Sagittal T1 image showing a 1.7 x 1.5 x 2cm pituitary macroadenoma. Pituitary stalk and remaining pituitary gland are deviated to the right (left). T1 coronal image showing the same macroadenoma invading into the cavernous sinus and wrapping around the ICA (right).

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