title: Fourth branchial sinus causing recurrent cervical abscess.
abstract: BACKGROUND
  Three patients who presented with recurrent cervical abscesses were found to have a branchial sinus arising in the piriform fossa. Each patient had previously had cervical abscess drainage procedures.
  
  
  METHODS
  A retrospective review of patients with recurrent cervical abscess and associated fourth branchial sinus was carried out.
  
  
  RESULTS
  In each case, imaging and endoscopy identified a sinus tract from the left piriform fossa. Neck exploration with hemithyroidectomy and excision of the sinus tract was performed without further recurrence of abscess.
  
  
  CONCLUSIONS
  We believe these cases to represent a fourth branchial sinus. The relevant embryology and anatomy of the branchial apparatus is discussed and the pathways for the sinus and fistulous tracts of branchial sinus origin are reviewed. Branchial sinuses are uncommon, but should be considered as the underlying aetiology in patients who present with recurrent cervical abscesses.
authors.affiliation: Department of Otolaryngology, University of Melbourne, Royal Victorian Eye and Ear Hospital, Australia.
authors.forename: P P
authors.initials: PP
authors.lastname: Burstin
authors.forename: R J
authors.initials: RJ
authors.lastname: Briggs
mesh_terms: D000038:Abscess / Q000209:etiology* / Q000601:surgery; D000293:Adolescent; D000328:Adult; D001935:Branchioma / Q000150:complications*; D005260:Female; D006258:Head and Neck Neoplasms / Q000150:complications*; D006801:Humans; D008297:Male; D010608:Pharyngeal Diseases / Q000209:etiology* / Q000601:surgery; D012008:Recurrence; D012189:Retrospective Studies