This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neck, Subject name: Surgery
Child with midline swelling in the neck most probable diagnosis 
Select and explain. 
A. Thyroglossal cyst, B. Thyroid, C. Cystic hygroma, D. Dermoid cyst
A: Thyroglossal cyst
Answer: A: Thyroglossal cyst 
Explanation: Ans. (a) Thyroglossal CystRef: Schwartz 10th edition, Page 1602* Midline masses include thyroglossal duct remnants, thyroid masses, thymic cysts, or dermoid cysts* Thyroglossal cysts account for about 75% of congenital midline swellings in childhood, and they are the most common abnormality of the midline neck seen in children