Complete bilateral second branchial cleft fistula in an adolescent: a rare case report with literature review.

Introduction: Branchial cleft anomalies are congenital defects resulting from incomplete obliteration of branchial apparatus during embryogenesis. Second branchial cleft anomalies are the most common type, typically presenting as cysts or sinuses. Complete fistulae are rare, and bilateral complete second branchial cleft fistulae are exceedingly rare, with only a few cases reported in the literature to date. Case Presentation: We present a case of a 17-year-old female with bilateral mucopurulent neck discharge since birth, worsening in recent months. Clinical examination revealed two cutaneous openings along the anterior border of the sternocleidomastoid muscle. Fistulography demonstrated bilateral linear tracts extending toward the tonsillar fossae, consistent with complete second branchial cleft fistulae. Audiological and renal evaluations were normal, effectively ruling out branchio-oto-renal syndrome. The patient was referred to a specialized otorhinolaryngology center for surgical excision. Discussion: This case highlights an exceptionally rare anomaly - bilateral complete second branchial cleft fistulae. The diagnosis can be easily missed or delayed due to its rarity and nonspecific presentation. Fistulography remains a reliable and cost-effective method for delineating the tract; meanwhile, MRI and contrast-enhanced CT provide excellent soft tissue detail and help identify the tract's relation to vital structures. Surgical excision is the definitive treatment, with the stepladder approach offering superior access and reduced recurrence in complex cases. Our case contributes valuable data to the limited literature and underscores the importance of considering bilateral anomalies in chronic or congenital neck discharges. Conclusion: Timely recognition and management of rare branchial anomalies are crucial to prevent recurrent infections and complications.