Symptoms of Branchial Cleft Cyst
Also, known as a cleft sinus, a branchial cleft cyst is a lump that develops in the neck or just below the collarbone. Branchial cleft cysts form during development of the embryo. They occur when tissues in the neck and collarbone area (branchial cleft) fail to develop normally. The birth defect may appear as open spaces called cleft sinuses, which may develop on one or both sides of the neck. A branchial cleft cyst may form from fluid drained from a sinus. The cyst or sinus can become infected. Symptoms of branchial cleft cyst include:

a dimple, lump, or skin tag on your child’s neck, upper shoulder, or slightly below their collarbone

fluid draining from your child’s neck

swelling or tenderness in your child’s neck, which usually occurs with an upper respiratory infection