SUN-287 Pituitary Gigantism Presenting as Anxiety

Overproduction of growth hormone in a young person with open epiphyses results in gigantism. Pituitary gigantism is rare and its cause is most often a pituitary adenoma. We present a 9 y.o. boy followed by his psychiatrist, referred for worsening anxiety and rapid growth. He had a history of mild anxiety in childhood with worsening of symptoms a year prior to the endocrine visit. He also had aggressive behavior, irritable mood and poor concentration. He was started on guanfacine with subsequent addition of escitalopram. He has been rapidly outgrowing his clothes and shoes (men’s size 9) and complains of heat intolerance. He was following along the 97(th) percentile for height with significant growth acceleration observed starting at age 7 y.o. Current height is at +2.8 SDS. Weight has increased from the 90(th) percentile to the 97th percentile since age 4 y.o. and currently at +2.3 SDS. His BMI was at the 95th percentile. Physical examination showed a prominent jaw, widely-spaced teeth, large hands and feet, Tanner I pubic hair, no axillary hair, testicular volume 3 ml bilateral. Initial bloodwork showed elevated IGF-1 at 925 ng/mL (+13.7 SDS). Random growth hormone level was elevated at 5.66 ng/mL. He had normal male karyotype, free T4 was 1.5 ng/dL, with TSH of 2.13 uIU/mL. Prolactin level was normal. Growth hormone level after an oral glucose load showed a nadir of 2.76 ng/mL. This confirms growth hormone excess. ACTH and cortisol levels were normal. FSH and testosterone levels were prepubertal. Intact PTH, calcium and phosphorus levels were all normal. Skeletal survey did not identify any fibrous dysplasia seen in McCune Albright syndrome. Echocardiogram did not show atrial myxoma associated with Carney complex. MRI of the brain and pituitary gland was obtained which showed 4mm x 5 mm pituitary microadenoma. He underwent transsphenoidal surgery. IGF-I level twelve weeks post-surgery had decreased to 384 ng/mL (+4.3 SDS) showing a good response to transsphenoidal surgery. Repeat growth hormone suppression test showed a nadir level of 0.66 ng/mL. Goal of treatment is to normalize IGF-I level based on age. On subsequent visit with his psychiatrist, behavior issues and anxiety have improved with plans to discontinue psychotropic medications. We report a case of growth-hormone secreting pituitary adenoma presenting with anxiety. Patients with pituitary adenomas show a distinct pattern of increased anxiety-related personality traits compared with the general population, proposed to be due to direct and indirect effects of the pituitary lesion or hormonal disturbance on neural circuits or neurotransmission. Symptoms of anxiety and depression are valuable targets for possible future treatment interventions.