Leukoplakia - Types, Causes, Risk Factors, Diagnosis, and Treatment

Introduction:

Leukoplakia is defined as a condition where one or more white patches or spotty lesions are noted to form at the mouth's inner surface. Leukoplakia varies from other oral lesions by their cause. Leukoplakia can progressively develop into oral cancer. Within 15 years of the incidence of leukoplakia, about 3 % to 17.5 % of the affected individuals are more likely to develop squamous cell carcinoma. It is a slow-growing type of tumor. The likelihood of developing squamous cell carcinoma from leukoplakia depends primarily on the size, shape, and appearance of abnormal cells.

What Are the Types of Leukoplakia?

Leukoplakia has been broadly classified into two different types, and they are as follows.

Homogenous Leukoplakia: In this type of leukoplakia, the lesion is mostly white. The lesion looks like a thin patch that usually has a smooth, wrinkled, or ridged surface.

Non-homogenous Leukoplakia: In this type of leukoplakia, the lesion is white or white and red. The structure of the patch is irregularly shaped. It may be flat or nodular. Non-homogenous leukoplakia is further sub-classified into ulcerated and nodular types. Classifying them can greatly help in the prediction of whether a patch will become cancerous or not.

Which Is the Most Aggressive Form?

Proliferative verrucous leukoplakia (PVL) is a rare and the most aggressive form. This condition is also known as florid papillomatosis. It is often associated with the Epstein-Barr virus. Epstein-Barr Virus (EBV) belongs to the herpes virus family. Almost all the affected individuals will eventually acquire cancer at several different sites. Proliferative verrucous leukoplakia is diagnosed as a late event in the development of leukoplakia. This is the reason that it takes a long time to spread to different sites. It has also been noted to have a high rate of recurrence.

What Is Oral Hairy Leukoplakia?

Oral hairy leukoplakia is also associated with the Epstein-Barr virus infection. Epstein-Barr infections usually stay in the affected person's body throughout their life. People with weak immune systems, like acquired immunodeficiency syndrome (AIDS) patients are affected. These people have a higher development of oral hairy leukoplakia when compared to others. The appearance of oral hairy leukoplakia can be explained as black hairy patches, often with folds. This structure makes it appear like the hair is growing out of the folds. These spots are commonly seen on the tongue, but they can develop in other parts of the mouth. Oral hairy leukoplakia does not develop into squamous cell carcinoma, unlike the other types. This condition is also commonly seen in homosexual males.

What Are the Causes of Leukoplakia?

The cause of leukoplakia is unknown most of the time. It is very frequently caused by chronic irritation with tobacco. Sometimes long-term users of smokeless tobacco products eventually develop leukoplakia at the location they hold the tobacco against their cheeks (buccal skin).

Other causes may include chronic irritation from:

• Jagged teeth due to any previous trauma, broken or sharp teeth that rub on the lateral tongue surfaces.

• Broken dentures or dentures that do not fit properly.

• Chronic usage of alcohol.

What Are the Risk Factors for Leukoplakia?

The following are the most frequently seen risk factors that lead to leukoplakia:

• Long-term tobacco use.

• Chronic alcohol use.

• Chewing tobacco.

• Acquired immunodeficiency syndrome.

• Ebstein-Barr virus infections.

• Inappropriately fitting dentures.

What Are the Clinical Features of Leukoplakia?

Leukoplakia usually occurs in the gums, the inner region of the cheeks, the floor of the mouth below the tongue, and, sometimes, superficially on the tongue. The initial stages of this condition usually do not cause any pain or discomfort. This causes it to go unnoticed for a while.

When symptoms start to appear, they have the following features.

• White or grayish in patches that cannot be scrapped from the surface, unlike the thrush of candidiasis.

• Irregular or flat in appearance.

• Intermittent thickened and hardened areas.

• Raised red lesions which are known as speckled leukoplakia or erythroplakia. These are signs that indicate that the lesion is developing its precancerous changes.

How Is the Condition of Leukoplakia Diagnosed?

The most commonly used methods in the diagnosis of leukoplakia are:

• Oral examination of patches present in the affected individual’s mouth.

• Attempting to scrape off the white patches.

• A thorough and focused medical history and looking for the presence of risk factors.

• Ruling out other possible causes such as candidiasis.

What Are the Types of Biopsy That Are Used for Leukoplakia?

A biopsy is a very useful diagnostic tool in identifying the condition of leukoplakia.

Oral brush Biopsy - This procedure involves the removal of cells from the superficial surface of the lesion with the help of a small, spinning brush. This is a non-invasive procedure but does not always help in achieving a definitive diagnosis.

Excisional Biopsy - This procedure involves the surgical removal of tissue from the leukoplakia patch, or the entire patch can also be removed if the lesion is small. An excision biopsy is more effective when compared to an oral brush biopsy, and it results in an appropriate diagnosis.

What Are the Treatment Options for Leukoplakia?

Treatment is very successful only when the lesion is found and treated early. A small lesion can be treated quickly. Regular follow-up visits with the doctor are needed. This is to routinely inspect the person's oral cavity to look for any signs of progression.

The leukoplakia can be managed by some of the following steps -

• Quit habits such as stopping tobacco or alcohol to prevent progression.

• Including fruits and vegetables in the diet.

• Taking supplements such as vitamin A- Retinoids may help in reducing the symptoms.

• If there is the presence of infection with the Epstein-Barr virus, antivirals are also usually prescribed to eradicate the virus.

If the disease has already progressed to a cancerous stage, then the patient would require surgical removal of the lesion, which includes procedures like -

• Surgical removal of the lesions. However, there is a slight chance that the lesions may recur and there might be a chance of the development of cancer in the areas treated with surgery.

• Using lasers to remove the lesions.

• Using an electrically charged needle or other instruments to remove the lesion (electrocauterization).

• Removing lesions using an extremely cold liquid or an instrument called a cryoprobe (cryotherapy).

• Using light-activated cancer drugs (photodynamic therapy).

Conclusion:

Leukoplakia is a common condition seen in patients with very poor oral hygiene and bad habits such as tobacco. This condition doesn't cause any permanent damage and can be treated with proper medications and making some lifestyle changes. However, it can increase the risk of developing cancer without any treatment. Therefore even the patient who is undergoing treatment for leukoplakia should follow up with the doctor every one or two months to check the recovery.