What is leukoplakia?
Leukoplakia is a condition in which one or more white patches or spots (lesions) forms inside the mouth.
Leukoplakia is different from other causes of white patches such as thrush or lichen planus because it can eventually develop into oral cancer. Within 15 years, about 3% to 17.5% of people with leukoplakia will develop squamous cell carcinoma, a common type of skin cancer.
The likelihood of developing cancer from leukoplakia depends on the size, shape, and appearance of abnormal cells.
What are the types of leukoplakia?
There are two main types of leukoplakia:
- Homogenous: A mostly white, evenly colored thin patch that may have a smooth, wrinkled, or ridged surface that is consistent throughout.
- Non-homogenous: A mainly white or white-and-red, irregularly shaped patch that may be flat, nodular (having protrusions), or verrucous (elevated). Additional sub-classifications, such as ulcerated and nodular (speckled), may also be made, and can help predict the likelihood that a patch will become cancerous.
Non-homogenous leukoplakia is seven times more likely to become cancerous than the homogenous type.
Proliferative verrucous leukoplakia (PVL) (also called florid papillomatosis) is a rare but especially aggressive form of oral leukoplakia. Studies show it is strongly associated with the presence of Epstein-Barr virus, a type of herpes virus. Nearly all cases will eventually become cancerous at a number of different sites. PVL is usually diagnosed late in the development of leukoplakia, as it takes time to spread to multiple sites. It also has a high rate of recurrence.
What are the causes of leukoplakia?
Leukoplakia is often associated with the following:
- Heavy smoking
- Use of chewing tobacco or snuff
- Chewing areca nut (also known as betel nut), which grows in the tropics of Asia, the Pacific, and parts of east Africa
- Heavy use of alcohol (although not all studies show this link)
Some leukoplakia is also idiopathic, meaning that there is no known cause.
Most cases occur in men who are between the ages of 50 and 70. Less than 1% of cases are in patients under the age of 30.
What are the symptoms of leukoplakia?
The symptoms of leukoplakia are one or more white patches on the surface of the tongue, underneath the tongue, or on the insides of the cheeks. The patches cannot be rubbed off and cannot be traced to any other cause. No pain or other symptoms are present.
Some research has shown that patches on the floor of the mouth, and the underside or sides of the tongue are more likely to be cancerous. However, not all studies agree that location is an important factor. The size of a patch has no link to whether it may become cancerous.
Factors that are strong indicators of leukoplakia transforming to cancer include the appearance of:
- White or red masses with a pebbled appearance
- Increased firmness