Introduction: Precocious puberty occurs is associated with initial increase in linear growth and acceleration of bone maturity presenting as advanced bone age with early epiphyseal fusion which ultimately results in short stature. Van Wyk Grumbach Syndrome (VWGS) is a rare syndrome associated with incomplete isosexual precocious puberty and macroadenoma seen in cases of longstanding, untreated hypothyroidism is associated with a delayed bone age. Complete resolution of all the features is seen after starting thyroid hormone replacement therapy.
Case report: An 8-yr-old girl child presented with history of cyclical vaginal bleeding for last 2 months. Her weight was 29 kg (75th90th centile) and height was 119 cm (at 10th25th centile). Her breast was tanner stage 4 with no axillary or pubic hair. Hormonal investigations revealed high FSH 3.02 mIU/ml (0.302.00 mIU/ml); low LH: 0.02 mIU/ml (<0.106.00 mIU/ml); elevated Prolactin: 195.46 ng/ml (2.8029.20 ng/ml), TSH: 750 μIU/ml (0.355.50 μIU/ml); low T3: 28.83 ng/dl (60.00181 ng/dl) and low T4: 0.06 μg/dl (4.5012.60 μg/dl). CEMRI Brain showed enlarged sella with a suprasellar mass suggestive of macroadenoma measuring 1.6(1.5 cm. Her radiological investigations revealed bone age of 5 years (Greulich and Pyles atlas). USG whole abdomen was normal. USG neck showed no abnormality. Anti TPO levels were <28.0 U/ml (<60.00 U/ml). Levothyroxine supplementation was started following which FSH, Prolactin and Thyroid Function Tests returned to normal levels. Repeat CEMRI Brain after 10 months showed complete resolution of macroadenoma. Vaginal bleeding stopped after 2 cycles and she again started having regular menstrual cycles at 12 years of age. At 13 years of age, her weight is 60 kg (90th97th centile) and Height is 148 cm (at 25th centile) and having Tanner stage 4 Breast development with regular menstrual cycles. Mechanism postulated in VWGS which was attributed to a hormonal overlap in pituitary feedback mechanism. TSH, FSH, LH and human chorionic gonadotropin (hCG) are glycoprotein hormones which share a common alpha subunit but different beta subunits. Thus, TSH, in high concentrations, stimulates the FSH receptor leading to an increase in gonadal size and precocious puberty.
27 - 29 Nov 2019
British Society for Paediatric Endocrinology and Diabetes