Leukoplakia: Types and Cancer Risk

What leukoplakia means

The term describes how a patch looks, not what it is. A clinician calls a patch "leukoplakia" only after ruling out other white lesions such as thrush, cheek biting, lichen planus or a burn. It is therefore a diagnosis of exclusion. The white color comes from extra keratin, the same tough protein found in calluses.

The World Health Organization classes oral leukoplakia as an oral potentially malignant disorder, meaning it can, in some cases, turn into squamous cell carcinoma. Most patches never do.

Types of oral leukoplakia

Site matters too. Patches on the floor of the mouth, sides and underside of the tongue and soft palate carry more risk than those on the cheeks or gums. More detail on mouth patches, including how to tell them from harmless white lesions, is on the oral leukoplakia page.

Other conditions called leukoplakia

Oral hairy leukoplakia

Hairy leukoplakia causes white, corrugated ridges, usually on the sides of the tongue. It is caused by Epstein-Barr virus in people with weakened immunity, especially HIV. It is not precancerous. It is often a sign that HIV or another immune problem needs testing or treatment.

Vocal cord (laryngeal) leukoplakia

White patches on the vocal cords cause hoarseness. They are closely linked to smoking and reflux, and some contain dysplasia or early laryngeal cancer. An ear, nose and throat specialist examines the cords with a scope, and most patches are removed or biopsied.

Vulvar and penile white patches

"Leukoplakia of the vulva" is an old term. Today most white, itchy patches of the vulva are lichen sclerosus or lichen simplex, and precancerous changes are called vulvar intraepithelial neoplasia. White patches on the penis can be lichen sclerosus (balanitis xerotica obliterans) or, rarely, penile intraepithelial neoplasia. Both need examination and sometimes biopsy.

Bladder leukoplakia

A rare finding during cystoscopy, linked to chronic irritation from infections, stones or catheters. It is followed up because of a small cancer risk.

Causes and risk factors

• Tobacco: smoking, chewing tobacco, snuff and betel quid or areca nut. Patches often form where the tobacco is held.
• Alcohol, which adds to the effect of tobacco.
• Chronic friction: rough teeth, dentures or cheek biting can cause similar white patches (frictional keratosis), which usually fade when the irritation stops. Strictly, these are not leukoplakia.
• Human papillomavirus (HPV): plays a role in some patches.
• Idiopathic leukoplakia: patches in people who have never smoked. These carry a somewhat higher risk of turning cancerous than smoking-related ones.

Symptoms

Leukoplakia is usually painless and is often noticed by a dentist. You may see or feel a patch that:

• is white or gray, flat or slightly raised
• feels thick, rough or leathery
• cannot be wiped or scraped away
• in higher-risk forms, has red flecks, lumps or a warty surface

Pain, bleeding, an ulcer or a firm lump suggest something more serious.

Diagnosis

1. Examination and removal of irritants (smooth a sharp tooth, adjust dentures, treat suspected thrush) with a recheck in about 2 weeks.
2. Biopsy of any patch that persists, taking samples from the most suspicious-looking areas. The pathologist reports whether there is no dysplasia, mild, moderate or severe dysplasia, or carcinoma.
3. Brush biopsy and special lights are sometimes used for screening but do not replace a tissue biopsy.

Treatment

• Stop tobacco and areca nut, and reduce alcohol: some patches shrink or disappear within months of quitting.
• Surgical removal with a scalpel or laser for patches with moderate or severe dysplasia, high-risk types, or high-risk sites.
• Close monitoring with photographs and repeat biopsy for small, low-risk patches.
• Lifelong follow-up: patches can recur after removal, and new ones can appear, so checks every 3 to 12 months are typical depending on risk.

No medicine reliably prevents progression. Hairy leukoplakia is treated by improving immune function (for example HIV treatment) and occasionally antiviral medicines.

Frequently asked questions

What is leukoplakia?

Leukoplakia is a white patch on a mucous membrane, usually inside the mouth, that cannot be rubbed off and has no other identifiable cause. It is linked to tobacco and alcohol. Most patches are harmless, but some contain precancerous cells, so persistent patches are biopsied.

What percentage of leukoplakia becomes cancer?

Estimates vary, but on average a small percentage of oral leukoplakias turn into cancer over several years, often quoted as about 1% to 3% a year. The risk is much higher with speckled, nodular or warty patches, proliferative verrucous leukoplakia, dysplasia on biopsy, and patches on the tongue or floor of the mouth.

Can leukoplakia go away on its own?

Some patches fade or disappear after stopping tobacco, alcohol or a source of friction, often within weeks to months. Patches that persist need a biopsy. Even if a patch goes away, the lining has been exposed to the same risks, so regular mouth checks are still advised.

Is hairy leukoplakia the same as leukoplakia?

No. Oral hairy leukoplakia is caused by Epstein-Barr virus in people with weakened immunity, usually on the sides of the tongue, and is not precancerous. Ordinary leukoplakia is linked to tobacco and can be precancerous. Hairy leukoplakia is a reason to test for HIV.

What does leukoplakia on the vocal cords mean?

It means a white patch on the vocal cords, usually causing hoarseness. It is linked to smoking, reflux and voice strain. Some patches contain dysplasia or early cancer, so an ENT specialist will examine the larynx with a scope and often remove or biopsy the patch.