This case represents a cystic lesion at the right side of the neck with the superomedial part curves behind the hyoid bone. As this corresponds to the course of thyroglossal duct, thyroglossal duct cyst was regarded as a first consideration.

Thyroglossal duct cyst can grow off midline and can have less common more lateral extensions such as extension along the anterior border of the sternocleidomastoid presenting as lateral neck swelling as in this case.

So, it should be well differentiated from second branchial cleft cyst. Thyroglossal duct cyst should be considered as a differential diagnosis in any cystic neck swelling.