Oral leukoplakia (OL) is a white patch or plaque that cannot be rubbed off, cannot be characterized clinically or histologically as any other condition, and is not associated with any physical or chemical causative agent except tobacco. Therefore, a process of exclusion establishes the diagnosis of the disease. In general, the term leukoplakia implies only the clinical feature of a persistent, adherent white plaque; therefore, reserve the term for idiopathic lesions when investigations fail to reveal any cause. The term carries absolutely no histologic connotation, although, inevitably, some form of disturbance of the surface epithelium is characteristic.
Follow-up studies suggest that cancer is more likely to occur in individuals with idiopathic leukoplakia than in individuals who do not have this condition. Thus, idiopathic leukoplakia is considered a premalignant lesion. [1, 2]
The etiology of most cases of OL is unknown (idiopathic). In other cases, the initiation of the condition may depend on extrinsic local factors and/or intrinsic predisposing factors. Factors most frequently blamed for the development of idiopathic leukoplakia include tobacco use, alcohol consumption, chronic irritation, candidiasis, vitamin deficiency, endocrine disturbances, and possibly a virus.
OL occurs in fewer than 1% of individuals.
OL is considered to be potentially malignant, with a transformation rate in various studies and locations that range from 0.6 to 20%.
A long-term follow-up study by Fan et al indicated that oral leukoplakia can increase the risk of esophageal squamous cell carcinoma (ESCC). The study, in which nearly 29,584 healthy adults were enrolled, found that 2924 persons in the study developed ESCC over a 28-year follow-up period; in adults aged 52 years or younger at baseline, the hazard ratio for the disease in those with leukoplakia was 1.31. 
OL is more common in men than in women, with a male-to-female ratio of 2:1.
Most cases of OL occur in persons in their fifth to seventh decade of life. Approximately 80% of patients are older than 40 years.
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Christopher M Harris, MD, DMD Residency Program Director, Department of Oral and Maxillofacial Surgery, Maxillofacial Tumor and Reconstruction, Naval Medical Center Portsmouth
Christopher M Harris, MD, DMD is a member of the following medical societies: American Association of Oral and Maxillofacial Surgeons, American Dental Association
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Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
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Nader Sadeghi, MD, FRCSC Professor and Chairman, Department of Otolaryngology-Head and Neck Surgery, McGill University Faculty of Medicine; Chief Otolaryngologist, MUHC; Director, McGill Head and Neck Cancer Program, Royal Victoria Hospital, Canada
Nader Sadeghi, MD, FRCSC is a member of the following medical societies: American Academy of Otolaryngology-Head and Neck Surgery, American Head and Neck Society, American Thyroid Association, Royal College of Physicians and Surgeons of Canada
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Arlen D Meyers, MD, MBA Professor of Otolaryngology, Dentistry, and Engineering, University of Colorado School of Medicine
Arlen D Meyers, MD, MBA is a member of the following medical societies: American Academy of Facial Plastic and Reconstructive Surgery, American Academy of Otolaryngology-Head and Neck Surgery, American Head and Neck Society
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David J Terris, MD, FACS Porubsky Professor and Chairman, Department of Otolaryngology, Medical College of Georgia, Georgia Regents University
David J Terris, MD, FACS is a member of the following medical societies: American Association for the Advancement of Science, Federation of American Societies for Experimental Biology, International Association of Endocrine Surgeons, Alpha Omega Alpha, Triological Society, Radiation Research Society, American Academy of Otolaryngology-Head and Neck Surgery, American Bronchoesophagological Association, American College of Surgeons, American Head and Neck Society, Phi Beta Kappa, Society of University Otolaryngologists-Head and Neck Surgeons
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