title: Nasopharyngeal carcinoma in situ (NPCIS)--pathologic and clinical perspectives.
abstract: BACKGROUND
  Dysplasia or carcinoma in situ lesions (NPCIS) of the nasopharynx have rarely been reported. The prevalence, biologic behavior, and the transformation period of the pure preinvasive lesions have not been fully explained.
  
  
  METHODS
  All cases of NPCIS were retrospectively reviewed during the period between 1990 and 2000. The clinical features of all cases were studied. The biopsy samples were examined using light microscopy and in situ hybridization (ISH) for EBV-encoded RNA (EBER). The sera taken before and after the transformation were analyzed for anti-viral capsid antigen (VCA) EBV titers and circulating cell-free EBV DNA concentration.
  
  
  RESULTS
  Three cases of NPCIS were identified. Two of the three cases subsequently developed into invasive NPC after initial presentation. The interval of transformation varied from 40 to 48 months. In all three cases, the specimens showed abnormal findings on light microscopy and positive staining for EBER. Elevated anti-VCA titers were present in two of the preinvasive lesions. No cell-free EBV DNA was detected in the sera of these patients during the preinvasive phase of the disease.
  
  
  CONCLUSIONS
  Preinvasive NPC is a rare but distinct entity. Its transformation period can be as long as 4 to 5 years. Elevated anti-VCA titers, in the presence of abnormal cells on light microscopy, should alert the pathologist to perform ISH EBER studies to diagnose this rare condition.
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 Wai
authors.initials: MW
authors.lastname: Pak
authors.forename: Ka Fai
authors.initials: KF
authors.lastname: To
authors.forename: Y M Dennis
authors.initials: YM
authors.lastname: Lo
authors.forename: Lisa Y S
authors.initials: LY
authors.lastname: Chan
authors.forename: J H M
authors.initials: JH
authors.lastname: Tong
authors.forename: Kwok Wai
authors.initials: KW
authors.lastname: Lo
authors.forename: Charles Andrew
authors.initials: CA
authors.lastname: van Hasselt
mesh_terms: D000328:Adult; D000368:Aged; D000956:Antigens, Viral / Q000097:blood; D015415:Biomarkers; D002213:Capsid / Q000276:immunology; D036022:Capsid Proteins / Q000097:blood; D002278:Carcinoma in Situ / Q000473:pathology*; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D004279:DNA, Viral / Q000032:analysis; D004854:Herpesvirus 4, Human / Q000276:immunology; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000473:pathology*; D012367:RNA, Viral / Q000032:analysis; D012189:Retrospective Studies; D014412:Tumor Virus Infections / Q000276:immunology / Q000473:pathology
chemical_list: D000956:Antigens, Viral; D015415:Biomarkers; D036022:Capsid Proteins; D004279:DNA, Viral; C041788:Epstein-Barr viral capsid antigen; D007070:Immunoglobulin A; D012367:RNA, Viral