[Pharyngeal branchial cyst: description of one clinical case].

Brachial cysts are abnormalities in the development of the branchial apparatus, being the more common ones those of the second arch. Cysts localized in the pharyngeal wall (Bailey's type IV) are extremely rare; therefore its differential diagnosis should include all benign and malignant lesions that can be found in the pharyngeal wall. Treatment is the total excision of the cyst through per oral or external cervical approach in order to avoid recurrences.