title: Case report of a p16INK4A-positive branchial cleft cyst.
abstract: OBJECTIVE
  To report the occurrence of a concurrent oropharyngeal papilloma and branchial cleft cyst linked by p16(INK4A) and human papillomavirus immunohistochemistry.
  
  
  METHODS
  A 42-year-old woman presented with a 1-month history of a left lateral neck mass. Contrast enhanced computed tomography showed a hypodense lesion 20 mm in diameter anteromedial to the left sternocleidomastoid muscle. Ultrasound-guided fine needle aspiration suggested a branchial cleft cyst. Panendoscopy was performed at the time of neck mass removal, and a papillomatous lesion was removed from the left hypopharynx. Histopathological analysis showed the neck lesion to be a branchial cyst containing lymphoid tissue, and the oral lesion to be a squamous papilloma. Immunohistochemical analysis showed both the branchial cleft cyst and papilloma to be positive for p16(INK4A) expression and human papillomavirus DNA.
  
  
  CONCLUSIONS
  Histological and immunohistochemical analyses support the cystic transformation of lymph nodes, or the 'Inclusion Theory', as the aetiology of branchial apparatus anomalies, and raise the possibility that human papillomavirus infection may play a much larger role in disease of the head and neck than previously supposed.
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery,Austin Hospital,Heidelberg,Melbourne.
authors.forename: T
authors.initials: T
authors.lastname: McLean
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery,Austin Hospital,Heidelberg,Melbourne.
authors.forename: C
authors.initials: C
authors.lastname: Iseli
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery,Austin Hospital,Heidelberg,Melbourne.
authors.forename: D
authors.initials: D
authors.lastname: Amott
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery,Austin Hospital,Heidelberg,Melbourne.
authors.forename: M
authors.initials: M
authors.lastname: Taylor
mesh_terms: D000328:Adult; D044963:Biopsy, Fine-Needle; D001935:Branchioma / Q000175:diagnosis / Q000378:metabolism*; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism*; D003937:Diagnosis, Differential; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D014057:Tomography, X-Ray Computed
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16
keywords: Branchioma; Papillomaviridae; p16INK4A