Piriform sinus fistula

The piriform sinus is an important structure in the hypopharynx, serving as the entrance for food into the esophagus. It is located on both sides of the laryngeal inlet in the hypopharynx, with one on each side. Piriform sinus fistula is a type of congenital branchial anomaly, belonging to a rare type of branchial cysts and fistulas in the neck. The fistula originates from the piriform sinus and terminates at the superior pole of the thyroid gland or behind the sternoclavicular joint, forming an internal fistula, often leading to recurrent purulent infections in the neck. Approximately 80% of cases occur during childhood. The main symptoms include recurrent neck infections or acute suppurative thyroiditis.