Pyriform sinus fistula.

Three patients had cervical draining sinus communicating with the pyriform sinus and one patient had acute suppurative thyroiditis resulting from infection through the pyriform sinus. There was a moderate to severe perithyroidal inflammation in all 4 cases. The age of onset ranged from 7 to 18 years old (mean; 12) but that of confirmation 9, 15, 18 and 67 years of age. Three of the patients were male and 3 of the cases involved the left side. All patients had suffered from several recurrences of cervical abscess, ranged from 2 to 7 times (mean; 4). Characteristic clinical features included 1) onset at a young age 2) frequent recurrence unless the fistula was extirpated completely 3) presenting with cervical draining sinus after repeated incision and drainage. It is supposed that the fistula is a route of infection mainly in the perithyroidal space and subsequently into the thyroid gland. When the fistula communicates directly with the thyroid gland, it can cause primary acute suppurative thyroiditis. Chronic cervical draining sinus with histories of repeated incision and drainage may be the clue to the diagnosis. A barium paste swallow study is the radiologic procedure of choice and complete removal of the fistula is the treatment of choice.