Clinical Features of Ectopic Thyroid Gland in Children: Single Center Experience

BACKGROUND/AIMS: Ectopic thyroid gland is the most common cause of permanent congenital hypothyroidism. Thus, this study aimed to examine the clinical and laboratory findings of patients with ectopic thyroid glands. MATERIALS and METHODS: Age of diagnosis, gender, presenting symptoms, anthropometric measurements, capillary thyroid-stimulating hormone (TSH) in neonatal screening, venous TSH and free thyroxine (FT4), thyroglobul in, IQ score, thyroid gland imaging results, and treatment doses were extracted from the patients' hospital files. RESULTS: Thus study included 26 patients (Female: 20) with the diagnosis of ectopic thyroid. The mean age of the diagnosis in patients born before the neonatal screening program (68.22 +/- 59.02 months) was higher than those born after neonatal screening (1.32 +/- 1.41) (p < 0.001). All patients had overt or subclinical hypothyroidism. The most common localization was the sublingual thyroid gland, which was detected in 23 patients (88.4%). The molecular genetic analysis of 16 patients with persistently elevated TSH and FT4 did not detect thyroid hormone receptor beta (TR beta) gene mutation. The Cattel intelligence test scores were within normal ranges, except for one case that had been diagnosed at the age of 4 years. Patients who had been diagnosed at the neonatal screening program had a better final height standard deviation score (p = 0.018) but without differences in the Cattel intelligence test scores (p = 0.373). TSH was normal in the sample of neonatal screening in one patient (TSH = 1.2 mu IU/mL). CONCLUSION: The majority of our patients with ectopic thyroid gland was female and had sublingual thyroid gland. Delayed diagnosis of overt and subclinical hypothyroidism due to neonatal screening unavailability, did not affect the psychomotor development but caused poor growth outcome. Neonatal screening cannot always detect the ectopic thyroid gland.