title: High malignant transformation rate of widespread multiple oral leukoplakias.
abstract: OBJECTIVE
  This study was undertaken in order to investigate clinicopathologic characteristics and malignant potential of widespread multiple oral leukoplakias.
  
  
  METHODS
  The present study includes 12 patients with widespread multiple leukoplakias (widespread patients) and 99 with localized lesions (localized patients), and all patients were followed for more than 6 months with the mean follow-up period of 4 years.
  
  
  RESULTS
  Gingiva and tongue were the major affected sites of leukoplakias in the localized patients, whereas gingiva and buccal mucosa were predominantly affected in the widespread patients. The rate of developing carcinoma was significantly (P < 0.02) higher in the widespread patients (3/12) than in the localized patients (5/99), although there was no significant difference in the rate of dysplastic lesions between these groups.
  
  
  CONCLUSIONS
  These results indicate that the widespread leukoplakias have a higher potential for the development of carcinoma than do the localized lesions.
authors.affiliation: First Department of Oral Surgery, Hokkaido University School of Dentistry, Sapporo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Saito
authors.forename: C
authors.initials: C
authors.lastname: Sugiura
authors.forename: A
authors.initials: A
authors.lastname: Hirai
authors.forename: K
authors.initials: K
authors.lastname: Notani
authors.forename: Y
authors.initials: Y
authors.lastname: Totsuka
authors.forename: M
authors.initials: M
authors.lastname: Shindoh
authors.forename: T
authors.initials: T
authors.lastname: Kohgo
authors.forename: H
authors.initials: H
authors.lastname: Fukuda
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002471:Cell Transformation, Neoplastic; D016009:Chi-Square Distribution; D018450:Disease Progression; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007972:Leukoplakia, Oral / Q000150:complications / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000453:epidemiology / Q000209:etiology* / Q000473:pathology; D011230:Precancerous Conditions / Q000473:pathology* / Q000601:surgery