2018 年 111 巻 1 号 p. 51-56
Pyriform sinus fistula, a congenital deformity derived from the third, fourth or fifth branchial cleft, is often the cause of acute suppurative thyroiditis and neck abscess among young subjects. It is mostly found on the left side. Herein, we report a rare case of a right-sided pyriform sinus fistula. A 28-year-old woman presented with a history of four episodes of right neck abscess in the previous four years. We suspected that the episodes of neck abscess were caused by the presence of a pyriform sinus fistula. However, neither CT nor barium hypopharyngography revealed the presence of a fistula. Finally, direct laryngoscopy under general anesthesia led to the diagnosis of the right-sided pyriform sinus fistula. After injection of pyoktanin into the fistula opening, the fistula was identified by a cervical approach and completely removed. The patient’s clinical course after the surgery was uneventful, and there has been no recurrence. Direct laryngoscopy is considered as a useful tool for the diagnosis of pyriform sinus fistula, especially when the fistula cannot be identified by any other modality, including barium hypopharyngography.