title: Oral lichen planus (OLP), oral lichenoid lesions (OLL), oral dysplasia, and oral cancer: retrospective analysis of clinicopathological data from 2002-2011.
abstract: BACKGROUND
  This 10-year retrospective study analyzed the incidence of malignant transformation of oral lichen planus (OLP). The study also included dysplasia and oral lichenoid lesion (OLL) in the initial biopsy as a potential differential diagnosis.
  
  
  METHODS
  A total of 692 scalpel biopsies were taken from 542 patients (207 [38.2%] men and 335 [61.8%] women). Clinical and histopathological parameters were analyzed.
  
  
  RESULTS
  The parameters gender (p = 0.022) and smoking behavior (p < 0.001) were significantly associated with the severity of diagnosis. Mucosal lesions with an ulcerative appearance (p = 0.006) and those located on the floor of the mouth (p < 0.001) showed significantly higher degrees of dysplasia or were diagnosed as oral squamous cell carcinoma (OSCC). Smoking and joint disease appeared to be significant risk factors. Treatment with tretinoin in different concentrations (0.005-0.02%) significantly improved diagnosis. Twelve patients (8 female, 4 male) showed malignant transformation to OSCC within an average period of 1.58 years. The malignant transformation rate (MTR) was higher for OLL (4.4%) than OLP (1.2%). If the first biopsy showed intraepithelial neoplasia, the risk of developing OSCC increased (by 3.5% for squamous intraepithelial neoplasia (SIN) II and by 6.7% for SIN III).
  
  
  CONCLUSIONS
  Although we cannot rule out that OLP is a premalignant oral condition, we can confirm that OLP had the lowest MTR of all diagnoses.
authors.affiliation: Department of Cranio-Maxillofacial and Oral Surgery, University Hospital Zurich, Plattenstrasse 15, 8032, Zurich, Switzerland, stephanie.casparis@hotmail.com.
authors.forename: S
authors.initials: S
authors.lastname: Casparis
authors.forename: J M
authors.initials: JM
authors.lastname: Borm
authors.forename: S
authors.initials: S
authors.lastname: Tektas
authors.forename: J
authors.initials: J
authors.lastname: Kamarachev
authors.forename: M C
authors.initials: MC
authors.lastname: Locher
authors.forename: G
authors.initials: G
authors.lastname: Damerau
authors.forename: K W
authors.initials: KW
authors.lastname: Grätz
authors.forename: B
authors.initials: B
authors.lastname: Stadlinger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D017676:Lichen Planus, Oral / Q000175:diagnosis* / Q000473:pathology*; D017512:Lichenoid Eruptions / Q000175:diagnosis* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009059:Mouth Diseases / Q000175:diagnosis* / Q000473:pathology*; D009061:Mouth Mucosa / Q000473:pathology; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D011230:Precancerous Conditions / Q000175:diagnosis* / Q000473:pathology*; D012189:Retrospective Studies; D055815:Young Adult