Abstract
Pyriform sinus fistula is a cause of repeated suppurative thyroiditis or neck abcesses. Between April 2006 and March 2011, we encountered four cases of pyriform sinus fistula. The fistula was removed via two approaches, namely, direct hypopharyngoscopy via an external incision. To visualize the fistula, a dye solution was injected during hypopharyngoscopy. The fistula was identified by its staining in two cases. In one of the two cases, a partial thyroidectomy was performed. In contrast, we were unable to detect the fistula in two cases, because no staining could be observed. In one of the nonidentified cases, a partial thyroidectomy was performed and a semithyroidectomy in combination with a fistulectomy was performed in the other. No recurrence was observed except in a pediatric case during the follow-up period. To prevent recurrence, complete identification and extirpation of the fistula are mandatory. The fistula should be identified by a procedure appropriate for each particular case. We concluded that thyroid lobectomy is necessary for preventing recurrence if the fistula cannot be identified by staining during surgery.