Delayed Diagnosis of Ectopic Thyroid Due to Ignored Borderline Result of Newborn Screening for Congenital Hypothyroidism

This case report highlights the importance of careful evaluation of borderline newborn screening results for congenital hypothyroidism, as demonstrated by an 8-year-old girl whose diagnosis of lingual thyroid-related congenital hypothyroidism was delayed. Despite a borderline thyroid-stimulating hormone level at birth, her condition was not identified until she presented with symptoms like constipation and cold intolerance. Physical examination revealed a lingual thyroid, confirmed by an isotope scan, and thyroid function tests indicated hypothyroidism. Her symptoms improved with levothyroxine therapy. The case emphasizes the need for thorough examinations to detect ectopic thyroid glands early, preventing future complications and ensuring timely treatment.