title: In vivo real-time diagnosis of nasopharyngeal carcinoma in situ by contact rhinoscopy.
abstract: BACKGROUND
  Nasopharyngeal dysplasia or nasopharyngeal carcinoma in situ (NPCIS) lesions have rarely been reported. Timely diagnosis of the preinvasive lesion may improve prognosis. Contact endoscopy has been documented to accurately differentiate normal cells of the nasopharynx from malignant cells and allows a real-time diagnosis of primary and recurrent nasopharyngeal carcinoma (NPC) in a clinical setting. However, the role of contact endoscopy in the diagnosis of NPCIS is unknown.
  
  
  METHODS
  The superficial cells of the nasopharynx in a patient with NPCIS were examined in vivo under local anaesthesia by use of a contact rhinoscope. The contact endoscopic findings were correlated with the histologic findings of the biopsy.
  
  
  RESULTS
  The atypical cells of the lesion were magnified and visualized under contact endoscopy. Histopathologic analysis of the biopsied tissue confirmed the presence of NPCIS staining positively for Epstein-Barr virus (EBV)-encoded RNA (EBER). No cell-free EBV DNA was detected in the sera of the patient.
  
  
  CONCLUSIONS
  Contact endoscopy can accurately identify the atypical cells of a tiny preinvasive lesion in the nasopharynx in a clinical setting, which may not be evident in routine imaging examination.
authors.affiliation: Division of Otorhinolaryngology, Department of Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, New Territories, Hong Kong, SAR, China.
authors.forename: Martin
authors.initials: M
authors.lastname: Wai Pak
authors.forename: Ka Fai
authors.initials: KF
authors.lastname: To
authors.forename: Joseph Chuen Kwun
authors.initials: JC
authors.lastname: Lee
authors.forename: Eisen Yee
authors.initials: EY
authors.lastname: Liang
authors.forename: Charles Andrew
authors.initials: CA
authors.lastname: van Hasselt
mesh_terms: D000328:Adult; D000956:Antigens, Viral / Q000235:genetics / Q000276:immunology; D001706:Biopsy; D036022:Capsid Proteins / Q000235:genetics / Q000276:immunology; D002278:Carcinoma in Situ / Q000175:diagnosis* / Q000473:pathology / Q000821:virology; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D004279:DNA, Viral / Q000097:blood; D004724:Endoscopy / Q000379:methods*; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D017403:In Situ Hybridization; D008279:Magnetic Resonance Imaging; D008297:Male; D009303:Nasopharyngeal Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000821:virology; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000032:analysis
chemical_list: D000956:Antigens, Viral; D036022:Capsid Proteins; D004279:DNA, Viral; C041788:Epstein-Barr viral capsid antigen; D012367:RNA, Viral