Leukoplakia is a condition in which thickened, white patches form on the tongue, gums, inside of the cheek, or sometimes on the outer female genitals. Although the sores can vary in appearance, they are usually white or gray; thick; and slightly raised with a hard surface. The condition is thought to be caused by irritation, but the cause is not always known. Tobacco is considered to be the main cause of its development in the mouth. Most patches are benign, but a small percentage show early signs of cancer. Removing the source of irritation may cause the condition to go away, but surgery to remove the sore(s) may be necessary in some cases.

Oral leukoplakia describes a white plaque that does not rub off and cannot be characterized as any other condition. Though it may occur in any part of the mouth, it generally affects the tongue, gums, and inner cheek. Physicians will usually biopsy oral leukoplakia lesions as 20-40% of cases are precancerous or cancerous at the time of biopsy and another 8-15% become cancerous over time. The exact cause of oral leukoplakia is not known. Factors that may increase the risk of developing oral leukoplakia include smoking, alcohol use, vitamin deficiencies, malocclusion, and a weakened immune system.Treatment depends on the biopsy results and the size, appearance, and location of the oral leukoplakia. Removal or ablation of the lesion by surgery, laser, or cryotherapy (use of low temperature) may be recommended.

Proliferative verrucous leukoplakia (PVL) is a rare type of oral leukoplakia, where white patches that have a high risk of becoming cancerous develop inside the mouth. It mainly involves the lining inside of the cheeks (buccal mucosa) and tongue. It starts as a white plaque of thickened skin (hyperkeratosis) that eventually spreads and forms rough, wart-like (verrucous) lesions that may look like cauliflower. The lesions are slow-growing and progressive, and more and more difficult to control over time. The risk of becoming cancerous is high, especially, of transforming to squamous cell cancer or verrucous carcinoma. It also has a high chance of coming back after treatment (high recurrence risk). The cause is unknown. In some cases, an association with human papilloma virus (HPV) infection has been noted. PVL is more common in elderly women who have had lesions of leukoplakia for many years. People with PVL should avoid certain factors currently known to be related to the development of oral cancer such as tobacco and alcohol. Treatment is not well established but may include surgery, laser ablation treatments, photodynamic therapy, and medication such as Methisoprinol. Because of the long-term course and high chance of becoming cancerous, people with this disease need to have regular follow-up.

Early signs of cancer may not be apparent. The clinical appearance of leukoplakia does not generally correlate with its appearance when examined under a microscope. For example, the lesion may appear unchanged for a period of time but may actually show changes when looked at under a microscope. Therefore, a biopsy is typically recommended in all cases to determine which lesions are precancerous. Small lesions may be biopsied and just followed periodically if it is shown to remain benign. However, those that show precancerous or cancerous features should be removed.

For most people, removing the source of irritation is important and often causes the lesion to disappear. For example, if tobacco use is thought to be the cause, stopping tobacco use usually clears the condition. Dental causes such as rough teeth or fillings should be treated as soon as possible. When this is not effective or if the lesions show early signs of cancer, treatment may include removing the patches. The lesion is usually removed in the health care provider's office using local anesthesia. Leukoplakia on the vulva is treated in the same way as oral lesions. Recurrences are common, so follow-up visits with a physician are recommended.

Leukoplakia usually does not cause complications or permanent damage. Sores often clear up a few weeks or months after the source of irritation is removed. Although most leukoplakia patches are benign (non-cancerous), a small percentage show early signs of cancer, and many cancers of the mouth occur next to areas of leukoplakia. Even after leukoplakia patches are removed, the risk of oral cancer remains higher than in the general population.Prognosis is better when leukoplakia is found and treated early.