부산대학교 도서관

Background: A fourth branchial cleft sinus (BCS) originates in the pyriform sinus apex of the hypopharynx and extends parallel to the recurrent laryngeal nerve (RLN). Although complete resection is still the mainstream treatment for a fourth BCS, combined thyroidectomy is often performed to reduce the recurrence rate. Methods: We report a case of a 53-year-old woman with a left anterior neck mass and progressive foreign body and compression sensations over a 3-month period. Neck ultrasonography showed bilateral thyroid nodules and a cystic lesion over the right superior thyroid region. Laryngofiberscopy revealed a lesion opening in the right pyriform sinus apex. A computed tomography scan further revealed a fourth BCS with extension of the upper right tracheoesophageal space. Results: Total thyroidectomy was performed by open trans-cervical approach with elective bilateral central neck dissection and resection of the right fourth BCS. The RLN, vagus nerve (VN), and external branch of the superior laryngeal nerve (EBSLN) were identified and preserved under intraoperative neuromonitoring (IONM). The pathology report showed left thyroid follicular carcinoma and right fourth BCS. Conclusions: To minimize the risk of injury to the RLN, VN, and EBSLN during thyroidectomy and fourth BCS resection, IONM can be used to identify nerves, avoid unnecessary dissection, simplify the surgery, and reduce the potential for injuries.