This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Thyroid Gland), Subject name: Surgery
Secretory sinus in neck, moving upon deglutination: 
Select and explain. 
A. Branchial sinus, B. Pilonidal cyst, C. Thyroglossal fistula, D. Sublingual dermoid cyst
C: Thyroglossal fistula
Answer: C: Thyroglossal fistula 
Explanation: Ans. (c) Thyroglossal fistulaRef: Dhingra's ENT 5th ed. / 398* Sublingual dermoid cyst present as midline submental swelling. This cyst is not attached to foramen cecum and hence doesn't move upon tongue protrusion or upon deglutition.* The thyroglossal cyst classically moves upwards with swallowing and notably with tongue protrusion, as it is attached to foramen cecum. It merely indicates attachment to the hyoid bone.