Background: The association of primary hypothyroidism and isosexual precocious pseudopuberty in females was first described in 1960 by Van Wyk and Grumbach. The unique elements that lead to the diagnosis are FSH-dominated sexual precocity with non advanced bone age in the presence of hypothyroidism.
Objective and methods: Describe an 8.5 years old girl with hypothyroidism due to HT and clinical and hormonal features of Van-Wyk and Grumbach syndrome.
Case report: An 8.5 years girl was referred to the endocrinology department with a suspicion of precocious puberty. She had no history of visual disturbance or headaches but was overweight for her height. On examination her height was 130.6 cm (50th centile), mid-parental height target was 159.5 (25th centile) her weight was 30 kg (75th centile) and she had breast development Tanners stage 23 with no pubic or axillary hair development. Hormonal investigations revealed high TSH levels at 32.46 μIU/ml (0.45) with low FT4 levels at 0.98 ng/dl (0.91.9) and positive thyroid peroxidase and thyroglobulin Abs (379.2 IU/ml (<16) and 543.6 IU/ml (<100) respectively), which confirmed HT. LHRH testing showed an FSH-dominated, prepubertal response with a 060 min FSH rise from 2.17 to 6.01 mIU/ml and an LH rise from 0.38 to 2.54 mIU/ml. Oestradiol levels were at 40.7 pg/ml (<27). Additional hormonal tests showed PRL levels at normal high range at 21.8 ng/ml (4.823.3) and normal testosterone: 2 ng/dl (220), DHEA-S: 69 μg/dl (2.885.2), 17-OHPRG: 0.57 ng/ml (0.20.5), β-HCG: <1 U/lt (<5) and α-FP levels:<2 ng/ml (<15 ng/ml). A pelvic ultrasound revealed a pubertal uterus (37×10×20 mm) and multicystic ovaries (RO: 5.4cc, LO:4.5cc) with multiple dominant follicles. In contrast to the pubertal Tanner stage 23 and the ultrasound appearance, the bone age was found to be equal to her chronological age. Thyroxine treatment was started at low dose of 25 μg/day and increased gradually to 50 μg/day. Clinical, hormonal and ultrasound findings returned to normal without additional therapy.
Conclusion: Autoimmune thyroiditis, although usually predisposes to delayed puberty it may also lead to isosexual precocious pseudopuberty. Recognition of this syndrome is important because thyroid hormone substitution completely resolves symptoms and hormonal abnormalities.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology