Silent internal sinus of the pyriform fossa: a rare adult manifestation of a branchial anomaly.

Branchial anomalies present with a wide range of pathologic characteristics, including cysts, fistulas, and sinuses of the head and neck region. Branchial cysts are most commonly diagnosed during the second through fourth decades of life, while branchial sinuses and fistulas are diagnosed almost exclusively in children with infection episodes. Only rarely has an internal sinus of a third or fourth branchial anomaly manifested in adults as a noninfectious swelling in the neck during swallowing. In this report, we describe our experience treating a 21-year-old man with a left-sided swallowing-induced neck protrusion of 10 years' duration. Findings of physical examination, videolaryngoscopy, and a pharyngoesophagogram confirmed the diagnosis of internal sinus of the pyriform fossa, with uncertain origin of a third or fourth branchial anomaly. The patient underwent regular follow-up as an outpatient and experienced no further infectious episodes.