SAT-520 Unusual Case of Hypothyroidism Possibly Due to Dialysis Leading to Van Wyk Grumbach Syndrome (VWGS)

BACKGROUND: Van Wyk Grumbach Syndrome (VWGS) is characterized by precocious central puberty in the setting of juvenile chronic primary hypothyroidism with symptom regression following thyroxine replacement. Clinical Case: A 2 year old girl with dysplastic kidneys and chronic renal disease had been treated by her nephrologist with growth hormone for poor growth. She was referred to Endocrinology for evaluation of bloody dialysate thought to be retrograde menstrual flow. Pelvic US showed bilateral large cystic adnexae possibly ovarian cysts versus septated collections of dialysate fluid. Hormone measurements showed pubertal levels of LH 0.4mIU/mL and FSH 5.4mIU/mL, with a relatively low Estradiol 5.3pg/mL. Brain MRI showed impressive pituitary enlargement measuring 1.3cm craniocaudally. Additional laboratory testing was notable for a low normal free T4 fT4 0.9ng/dL and markedly elevated TSH>1000uIU/mL and Prolactin 835ng/mL. Thyroid US showed thyroid enlargement, and echogenic and hyper vascular gland. Anti-thyroid antibodies titers were normal, AM cortisol and IGF1 were also normal for age. We speculate that this case of profound hypothyroidism was due to dialysis, as thyroid function improved after the child underwent renal transplantation. Levothyroxine was discontinued 5 months after renal transplantation. Elevated TSH may induce a form of pseudopuberty as the TSH alpha subunit is similar to that of LH and binds to the LH receptor to stimulate the ovaries with cyst formation. Conclusion: In VWGS, primary hypothyroidism with elevated TSH induces central precocious puberty. This child’s bloody diasylate was likely the result of transient central precocious puberty associated with uncontrolled primary hypothyroidism with elevated TSH and prolactin. Although the literature on dialysis suggests minimal thyroid hormone losses, this case shows the importance of monitoring thyroid hormones in dialysis patients. Early recognition of VWGS and initiation of thyroid hormone replacement can lead to resolution of symptoms.