A Type I first branchial cleft cyst masquerading as a parotid tumor.

Branchial cleft anomalies are caused by incomplete regression of the cervical sinus of "His" during the 6(th) and 7(th) weeks of embryologic development. Although congenital in origin, first branchial cleft cysts (FBCCs) can present later in life. FBCCs are rare causes of parotid swellings, accounting for <1% of all the branchial cleft abnormalities. The diagnosis of FBCCs is a clinical challenge; the condition is often overlooked and mismanaged. We report a case of Type 1 FBCC in a 22-year-old female with an asymptomatic 3.5 cm × 2.5 cm sized cystic mass. It was removed completely under the impression of a cystic tumor of the parotid. On histopathology, the cyst had a squamous epithelium-lined wall with lymphoid aggregation which was characteristic of a branchial cleft cyst. A good understanding of the regional anatomy and embryology can lead to an early diagnosis and thereby effective management of FBCC.