Large thyroglossal duct cyst of the neck mimicking cervical cystic lymphangioma in a neonate: a case report

Thyroglossal duct cyst (TGDC) is a congenital neck malformation, with a rate of approximately 7% in paediatric patients. TGDC is rarely detected in infants aged younger than 1 year. Even though TGDC is histologically benign, it is associated with preterm delivery or sudden infant death due to airway obstruction, with a mortality rate of 30% to 40%. We report a rare case of a neonate who presented with a large left lateral neck mass. At 7 to 8 months of gestation, magnetic resonance imaging of the foetal neck showed that there was a high possibility of a cervical cystic lymphangioma. The patient had normal vital signs and was afebrile. She was immediately transferred to our Ear, Nose, and Throat Department for further diagnosis and treatment. A computed tomography scan confirmed a large cystic mass that was positioned against a thyroglossal duct. Excision of the mass in the left neck was performed under general anaesthesia without resecting part of the hyoid bone. A histopathological examination confirmed the diagnosis of a TGDC. Follow-up at 1 year showed no recurrence.