A<unk>  is a cyst as a swelling in the upper part of neck anterior to sternocleidomastoid. It can, but does not necessarily, have an opening to the skin surface, called a fistula. The cause is usually a developmental abnormality arising in the early prenatal period, typically failure of obliteration of the second, third, and fourth<unk><unk> , i.e. failure of fusion of the second<unk>  arches and epicardial ridge in lower part of the neck.<unk> s account for almost 20% of neck masses in children. Less commonly, the cysts can develop from the first, third, or fourth<unk> s, and their location and the location of associated fistulas differs accordingly.
Branchial cleft cyst
Vascular anomaly
Thyroglossal cyst
Lymphadenopathy
Paradental cyst
Lymphoma
Vocal cord cyst
Thymus