INTRODUCTION: Thyroglossal duct cysts result from a failure of duct obliteration produced during embryonic migration of the thyroid. A cyst may develop from the residual epithelium at any point along the secretory thyroglossal duct. OBJECTIVE: The aim of this study is to report a case of thyroglossal duct cyst at the base of the tongue in a child. The child in question presented with a framework of predominant mouth breathing secondary to hypertrophy of the tonsils and adenoids, and diagnosis of thyroglossal cyst was incidental. CONCLUSION: Although these lesions are common in the midline, thyroglossal duct cysts can appear less frequently at locations such as the base of the tongue. Therefore, it is concluded that there is need for a high index of suspicion, with these cysts at the front of the differential diagnosis of midline cervical masses.
