Branchial cleft cyst

Branchial cyst
Other names	Branchial arch fistula Benign cervical lymphoepithelial cyst Pharyngeal arch cyst
Fistulogram (sinogram) of a right branchial cleft sinus.
Specialty	Medical genetics
Symptoms	Painless, firm mass lateral to midline, usually anterior to the SCM, which does not move with swallowing
Causes	Family history
Differential diagnosis	Vascular anomaly, dermoid cyst, thymic cyst, lymphadenopathy, lymphoma, HPV-related oropharyngeal cancer
Treatment	Conservative, surgical excision

A branchial cleft cyst or simply branchial cyst 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 branchial cleft, i.e. failure of fusion of the second branchial arches and epicardial ridge in lower part of the neck. Branchial cleft cysts account for almost 20% of neck masses in children.^[1] Less commonly, the cysts can develop from the first, third, or fourth clefts, and their location and the location of associated fistulas differs accordingly.