Branchial cleft cyst

What it is

A branchial cleft cyst is a remnant of the second branchial cleft, the most common of them, and it comes from failure of obliteration of that cleft. It is a congenital lateral neck mass, and it sits among the anterior triangle masses alongside submandibular abscess, thyroid nodule and laryngocele.

Three types of malformation come out of the same failure:

• Branchial fistula: persistent communication between skin and GI tract.
• Branchial sinus: blind-ended tract opening to skin.
• Branchial cyst: persistent cervical sinus with no external opening.

How it presents

It is a smooth, painless, slowly enlarging lateral neck mass of the anterior triangle, often following a URTI. The swelling is in the upper part of the neck anterior to the sternocleidomastoid muscle, in the upper third of the anterior neck triangle, and it may lie between the sternocleidomastoid muscle and the pharynx. It is smooth, round, non-tender, fluctuant and non-transilluminant, and it does not move on tongue protrusion or during swallowing. If it becomes infected there is erythema and tenderness, and it gives a painful increase in size at the time of a URTI. A branchial cyst is typically a benign, lateral, unilateral neck mass.