title: Keratosis of unknown significance and leukoplakia: a preliminary study.
abstract: OBJECTIVE
  The objectives were to (1) determine the frequency of specific diagnoses in a series of white lesions, and (2) describe the nature of keratotic lesions that are neither reactive nor dysplastic.
  
  
  METHODS
  White lesions were analyzed and diagnosed as reactive keratoses, dysplastic/malignant, or keratoses of unknown significance (KUS).
  
  
  RESULTS
  Of the 1251 specimens that were evaluated, 703 met criteria for inclusion, and approximately 75% were reactive, 10% dysplastic/malignant, and 14% KUS. Excluding reactive keratoses, 43% were dysplastic/malignant and 57% were KUS.
  
  
  CONCLUSIONS
  Reactive keratoses were the most common white lesions followed by lichen planus. Dysplastic/malignant lesions constituted almost 50% of all true leukoplakias. KUS constituted the remaining cases and do not show typical reactive histopathology as well as clear dysplasia. They may represent evolving or devolving reactive keratoses but may also represent the very earliest dysplasia phenotype. Clinical findings may be helpful in differentiating the two.
authors.affiliation: Associate Professor, Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, MA, USA; Associate Pathologist, StrataDx, Lexington, MA, USA; Attending Dentist, Division of Oral Medicine and Dentistry, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Sook-Bin
authors.initials: SB
authors.lastname: Woo
authors.affiliation: Resident in Oral and Maxillofacial Surgery, Department of Oral and Maxillofacial Surgery, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Grammer
authors.affiliation: Associate Professor, Department of Oral Pathology, Oral Medicine, and Craniofacial Pain, Tufts University School of Dental Medicine, Boston, MA, USA. Electronic address: Mark.Lerman@tufts.edu.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Lerman
mesh_terms: D005260:Female; D006801:Humans; D007642:Keratosis / Q000453:epidemiology* / Q000473:pathology; D007972:Leukoplakia, Oral / Q000453:epidemiology* / Q000473:pathology; D008297:Male; D009062:Mouth Neoplasms / Q000453:epidemiology* / Q000473:pathology; D011230:Precancerous Conditions / Q000453:epidemiology* / Q000473:pathology; D015995:Prevalence; D012307:Risk Factors