Internal cysts and fistulae of branchial origin.

Cysts and fistulae related to the second and third pharyngeal pouches are described. These anomalies probably occur more often than presumed. Unilateral recurring infections of the tonsillar region, including parapharyngeal abscess, may be caused by anomalies related to the second pouch. Third pouch anomalies are located in the piriform recess. Cysts may reach a size that causes obstruction to the larynx and hypopharynx, while diverticulae cause few symptoms.