Thyroglossal duct cysts are typically benign and usually asymptomatic. Malignant transformation is uncommon. Intralaryngeal extension is rare and results in dysphonia or dyspnea. There is no literature nowadays reporting the thyroglossal duct cyst carcinoma combining the clinical features of intralaryngeal extension. The authors present a case of progressive hoarseness and midline neck mass for 2 years. The laryngoscope and computed tomography revealed a 6-cm thyroglossal duct cyst containing ectopic thyroid tissue with intralaryngeal extension and causing airway obstruction. Complete excision with Sistrunk operation revealed papillary thyroid carcinoma. The patient resumed normal phonation after the surgery. There was no evidence of tumor recurrence and no hoarseness or dyspnea at 6 months follow up. This is the first reported case of a huge thyroglossal duct cyst carcinoma with intralaryngeal extension causing airway compromise. Complete excision of tumor is essential and vital to the symptom relief. A thyroglossal duct cyst carcinoma with endolaryngeal involvement should be considered in the differential diagnosis when the case has a massive midline neck mass with ectopic thyroid tissue and develops dyspnea or hoarseness concurrently.
Keywords: airway compromise; airway obstruction; endolaryngeal extension; intralaryngeal extension; thyroglossal duct carcinoma; thyroglossal duct cyst carcinoma.