title: Malignant transformation of oral lichen planus.
abstract: OBJECTIVE
  To investigate the malignant potential of oral lichen planus (OLP), a common mucocutaneous disease of unknown aetiology. The malignant potential of OLP is still controversial, with studies reporting malignant transformation rates of between 0 and 5.6%. We also aimed to identify factors that might be associated with malignant transformation.
  
  
  METHODS
  We retrospectively reviewed the records of 832 patients with histologically confirmed OLP treated at the Dental Hospital, Newcastle upon Tyne during the period 1983-1996.
  
  
  RESULTS
  Of these 832 patients, a total of seven (0.8%) developed intra-oral squamous cell carcinoma (SCC), including three cases of carcinoma in situ. It was noted that OLP patients with SCC are more likely to be women, relatively young and have a low tobacco and alcohol intake. However, they had a good long-term prognosis.
  
  
  CONCLUSIONS
  We conclude that the risk of malignant transformation in OLP is real but not high. Clinicians should have a higher index of suspicion of the possibility of malignancy developing in OLP, because such patients are different from typical patients who develop oral malignancy. Follow-up for at least 6 years is recommended.
authors.affiliation: The Medical School, University of Newcastle, Framlington Place, Newcastle upon Tyne, UK.
authors.forename: R
authors.initials: R
authors.lastname: Rajentheran
authors.forename: N R
authors.initials: NR
authors.lastname: McLean
authors.forename: C G
authors.initials: CG
authors.lastname: Kelly
authors.forename: M F
authors.initials: MF
authors.lastname: Reed
authors.forename: A
authors.initials: A
authors.lastname: Nolan
mesh_terms: D000328:Adult; D002278:Carcinoma in Situ / Q000209:etiology / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000209:etiology / Q000473:pathology; D002471:Cell Transformation, Neoplastic; D005260:Female; D006801:Humans; D017676:Lichen Planus, Oral / Q000473:pathology*; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000209:etiology* / Q000473:pathology*; D012189:Retrospective Studies; D012306:Risk; D012307:Risk Factors