Which neck mass is characterized by midline position and movement with the tongue?

• A. Branchial cleft cyst
• B. Thyroglossal duct cyst
• C. Cystic hygroma
• D. Enlarged lymph node

Answer: (B)

A neck mass that is characterized by its midline position and movement with the tongue is typically a thyroglossal duct cyst. This type of cyst originates from the remnants of the thyroglossal duct, which is a developmental structure that normally disappears during the descent of the thyroid gland.

The defining feature of a thyroglossal duct cyst is its anatomical location and its behavior. It is often situated in the midline of the neck, usually near the level of the hyoid bone. A key characteristic of this type of cyst is that it moves upwards with tongue protrusion or swallowing, due to its connection to the hyoid bone via fibrous tissue.

In contrast, other types of neck masses do not exhibit this specific movement. For instance, a branchial cleft cyst is usually found laterally in the neck and does not move with tongue activity. A cystic hygroma is typically unilocular or multilocular, often located posteriorly and doesn't exhibit the same mobility. An enlarged lymph node is usually associated with cervical lymphadenopathy and would feel firm and fixed rather than mobile with tongue movements. This distinction makes the thyroglossal duct cyst unique among neck masses.