Branchial cyst is due to a congenital defect that occurs early in embryonic development. It is the most common congenital cause of a neck mass which results from a failure of obliteration of one of the branchial clefts during embryonic development. No ethnic or sexual predilection has been reported. Approximately 2-3% of cases are bilateral. A tendency for familial clustering has been documented . Branchial cysts may not present clinically until early adulthood. They may become enlarged and tender especially following an upper respiratory tract infection. Sudden rupture of an abscess which has developed inside a branchial cyst may lead to the formation of a discharging sinus. Depending on the size of the branchial cyst local symptoms such as dysphagia, dysphonia or dyspnoea may occur .
We present a case report wherein the patient underwent excision of a branchial cyst on the right side of the neck which revealed squamous cell carcinoma in its lining.