(0724) Second Arch Branchial Cysts: Variable Presentations and New Classification

Introduction: Second branchial cleft cysts are relatively common cause of lateral neck swellings. Variable anatomical locations may exist in relation to great neck vessels. This work present our experience for such cases.

Methods: Retrospective case series in tertiary university referral hospital. Records of Fifty-three cases of second branchial cleft cysts operated from 2003 - 2023 were analysed. Pre-operative radiological assessment included non-contrast computed tomography (CT) scan +/- magnetic resonance (MR) imaging. Cyst location, operative findings, complications and postoperative follow-up were reviewed. A new classification for second branchial cleft cysts is proposed.

Results: Study included 26 males and 27 females, with mean age 38 years. The majority of our cases (83%) (44 cases) were found to be of the classic type IIa (Bailey’s type II). These cases included one patient presented with a recurrent BCC, and another recurrent one that was harboring papillary thyroid carcinoma (PTC). Other variable presentations included a case a multilocular BCC (1.9%), two cases of BCC with an external sinus (3.6%), and one BCC with a complete fistula (1.9%). Three cases (5.6%) were found to be lying anterior to the carotid vessels whereas only one case (1.9%) was found to be lying posterior to the carotid vessels.

Conclusions: A through preoperative radiological assessment is essential for the accurate surgical resection of branchial cysts. Awareness of atypical presentations and preoperative knowledge of vascular relations help reducing the incidence of complications. Our proposed new classification for type II second arch branchial cysts include all the possible variants that could be encountered.