R. NICKBRYANMDS. JAMESZINREICHMD
Branchial cleft cysts are congenital anomalies of the closure of the cervical sinus of His, although they rarely appear at birth and are usually diagnosed in late childhood or adulthood. Wild et al,1 studying the biochemistry of the keratins of the epithelial layer of these lesions, proposed an acquired origin in the epithelial cells in crypts of lymphoid tissue. If we accept the congenital origin of branchial cleft cysts, those derived from the second branchial cleft are by far the most common.2 These cysts appear frequently as a soft swelling in the neck, anterior to the sternocleidomastoid muscle, and they sometimes have a tract or a cutaneous fistula. The tract, if any, follows the carotid sheath and can go between the internal and external carotid arteries, ending in the lateral pharyngeal wall, close to the tonsil. Bayley3 and Proctor4 classified branchial cleft cysts into 4 types according to their location. Types I and II are situated lateral to the carotid artery, while type III is located lateral and may extend between the external and internal carotid arteries. The cyst described herein is type IV. It was located in the parapharyngeal space, medial to the great vessels of the neck.
Imaging Quiz Case 2. Arch Otolaryngol Head Neck Surg. 1998;124(5):605. doi:10.1001/archotol.124.5.602