Laryngeal Leukoplakia

Laryngeal leukoplakia appears as white patches on the vocal folds and can range from harmless to precancerous or even cancerous. Understanding this condition is crucial because early detection and proper treatment can prevent serious complications.

Table of contents

• What Is Laryngeal Leukoplakia?
• Associated Anatomy
• Types of Laryngeal Leukoplakia
• What Causes Laryngeal Leukoplakia?
• Risk Factors
• Symptoms
• How Is Laryngeal Leukoplakia Diagnosed?
• Understanding the Cancer Risk
• Treatment Options

What Is Laryngeal Leukoplakia?

Laryngeal leukoplakia is a condition characterized by white patches or plaques that appear on the surface of the vocal folds, which are part of the larynx (voice box). The term “leukoplakia” literally means “white plaque” in medical language^[2]. These white patches develop due to an accumulation of keratin, a protein naturally found in skin cells, on the vocal fold surface^[2].

The condition is considered important because it represents a wide spectrum of pathology. While some leukoplakia patches are harmless, others may be precancerous or even contain hidden cancer^[3]. The World Health Organization has refined the definition over time to describe leukoplakia as “white plaques of questionable risk having excluded other known disease or disorder that carry no increased risk for cancer”^[3].

Laryngeal leukoplakia can appear as either a flat, smooth patch or as a raised, thick area on one or both vocal folds^[1]. The white appearance comes from increased growth of cells on the surface of the vocal folds^[1].

• Larynx (voice box)
• Vocal folds (vocal cords)

Types of Laryngeal Leukoplakia

Laryngeal leukoplakia can be classified into different types based on how the patches look and their potential to become cancerous.

One classification system divides leukoplakia by appearance into three main types. Flat and smooth leukoplakia appears as even, flat white patches on the vocal fold surface. Elevated and smooth leukoplakia has raised areas but maintains a relatively smooth surface. Rough leukoplakia has an irregular, bumpy texture^[8].

Another way to classify leukoplakia is by its potential risk. Homogenous leukoplakia shows patches that are relatively even in color and texture throughout and usually does not progress to cancer. Non-homogenous leukoplakia has oddly shaped patches that may be white or red, flat or raised, and is more likely to become cancer. Proliferative verrucous leukoplakia, a rare type, shows small white patches that may grow quickly and have a bumpy surface. Research shows this type may become cancer in more than 60% of people who have it^[16].

On average, approximately 50% of laryngeal leukoplakia cases are associated with normal tissue under the white plaque. However, the other 50% are associated with some abnormality, ranging from dysplasia (abnormal cell changes that are not cancer but may progress to cancer) to actual cancer^[2].

What Causes Laryngeal Leukoplakia?

Laryngeal leukoplakia develops primarily from chronic irritation to the vocal fold tissues. The most common causes include smoking cigarettes and heavy alcohol consumption^[1][6]. The medical history of people with this condition most often shows at least one of these two risk factors^[6].

Additional factors that may promote the development of leukoplakia include laryngopharyngeal reflux, which is the backflow of stomach acid into the throat and voice box area^[1][6]. Environmental exposure to irritants can also contribute to the condition^[1].

Leukoplakia can also develop as a result of chronic inflammation of the larynx, called chronic laryngitis. In patients suffering from years of persistent chronic laryngitis, mostly due to habitual cigarette smoking, leukoplakia can develop first and may then progress to cancer of the vocal fold^[6].

In some cases, the condition may be caused by irritation from dental work, such as rough teeth, fillings, crowns, or dentures that don’t fit properly and rub against tissues^[7]. Voice misuse or overuse may also contribute to chronic irritation that leads to leukoplakia^[7].

Risk Factors

Certain factors increase the likelihood of developing laryngeal leukoplakia. Cigarette smoking is the major risk factor for both the development of laryngeal leukoplakia and its potential progression to cancer^[12][19].

Regular heavy alcohol consumption is another significant risk factor^[1][7]. Environmental exposure to irritants over long periods can also increase risk^[1].

People with ongoing acid reflux affecting the throat and larynx, known as laryngopharyngeal reflux, are at increased risk^[1]. Those who frequently misuse or overuse their voice may also be at higher risk^[7].

The condition affects men much more frequently than women, with a rate of about 10.2 per 100,000 in males compared to 2.1 per 100,000 in females. The typical age range for diagnosis is between 55 and 65 years, with the median patient age being around 61 to 63 years^[6][12][19].

Symptoms

The most common symptom of laryngeal leukoplakia is hoarseness or a raspy quality to the voice^[1][2]. People may also experience a rough voice quality, vocal strain when speaking, and vocal fatigue where the voice tires easily during use^[1].

The severity of voice symptoms varies depending on the size and location of the white patches on the vocal folds^[1]. In some cases, particularly when the patches are small or located in certain areas, leukoplakia may cause no noticeable symptoms at all and may be discovered only during a routine examination^[2].

The voice changes caused by leukoplakia are usually painless^[7]. However, in rare cases, the affected areas may be sensitive to touch, heat, or spicy foods.

How Is Laryngeal Leukoplakia Diagnosed?

Diagnosing laryngeal leukoplakia requires specialized examination by a doctor who specializes in conditions of the larynx, called a laryngologist. The diagnostic process typically begins with a thorough discussion of symptoms and medical history, including questions about smoking, alcohol use, and other risk factors^[1].

The main diagnostic tool is laryngoscopy, which remains the primary method for recognizing leukoplakia patches in the throat^[12][19]. During this procedure, a small camera is inserted through the nose or mouth to view the larynx and vocal folds directly^[1].

Video laryngostroboscopy is an enhanced version of this examination that uses special lighting to assess both the health and movement function of the vocal folds. This technique is particularly helpful for visualizing patches located at the edge of the vocal folds where they come together^[1][12].

Advanced imaging techniques can provide additional information. Narrow band imaging uses blue-light wavelength filtering to help identify potentially cancerous areas^[3][12]. Contact endoscopy for early diagnosis is also gaining interest as a diagnostic tool^[12].

However, visual examination alone cannot determine with certainty whether a white patch is benign, precancerous, or cancerous. Therefore, a biopsy is essential for proper diagnosis^[1][2]. During a biopsy, a small sample of tissue is removed from the leukoplakia patch and sent to a laboratory where it is examined under a microscope by a pathologist. This laboratory analysis can reveal whether there are abnormal cell changes or early signs of cancer^[1].

The biopsy may be performed using different techniques. An oral brush biopsy removes cells from the surface of the patch using a small spinning brush, though this doesn’t always provide a definite diagnosis. An excisional biopsy removes a piece of tissue from the patch and usually provides a more definite diagnosis. In some cases, if the patch is small, the entire patch may be removed during the biopsy procedure^[2].

Understanding the Cancer Risk

One of the most important aspects of laryngeal leukoplakia is its potential to harbor or develop into cancer. Both benign and dysplastic leukoplakia patches carry some risk of transformation to cancer^[12][19].

Research shows that in approximately 50% of cases, the white patches are associated with some cellular abnormality ranging from dysplasia to actual cancer^[2]. In one study of 296 vocal folds affected by leukoplakia, invasive cancer was found in 13.9% of cases when tissue was examined^[4].

The type and appearance of leukoplakia affects cancer risk. Rough-textured leukoplakia has a significantly higher cancer risk than smooth leukoplakia. Studies have found that the incidence of cancer in rough leukoplakia was 44.4% compared to only 2.4% in smooth leukoplakia^[8].

Visual inspection does not allow certain exclusion of cancer underneath the white plaque^[6]. This is why laryngeal leukoplakia is sometimes described as “an invasive cancer hidden within the vocal folds”^[4]. Even if a previous biopsy showed normal tissue, any new leukoplakia must be re-evaluated, as the condition can change over time^[11].

Treatment Options

Treatment for laryngeal leukoplakia depends on several factors, including the severity of symptoms, the size and location of the patches, whether dysplasia or cancer is present, and the patient’s overall health and risk factors.

Non-Surgical Treatment

For many cases of leukoplakia, especially smooth types without concerning features, non-surgical treatment may be appropriate. The first and most important step is eliminating the source of irritation. This means stopping tobacco use and reducing or eliminating alcohol consumption^[1][8].

Other non-surgical treatments may include voice rest to reduce irritation from speaking, medications to control acid reflux such as omeprazole, and in some cases, traditional Chinese herbal medicine therapy^[8]. For some patients, close observation without immediate active treatment may be appropriate, especially when symptoms are mild^[1].

Research has shown that non-surgical treatment can be effective, particularly for smooth leukoplakia. In one study, the complete response rate was 80.3% for flat and smooth leukoplakia and 66.0% for elevated and smooth leukoplakia after six months of non-surgical treatment. However, rough leukoplakia did not respond well to non-surgical approaches, with a 0% complete response rate^[8].

Voice therapy designed to reduce strain and improve efficient use of the voice may also help, especially when voice misuse contributes to chronic irritation^[7].

Surgical Treatment

Surgery is indicated when non-surgical treatment does not resolve the white patches after about 10 days of anti-inflammatory therapy, or when biopsy results show dysplasia or cancer^[11]. More aggressive treatment should be considered for rough leukoplakia due to its high cancer risk^[8].

The surgical procedure typically performed is called microlaryngoscopy with removal of the leukoplakia patch^[2]. Modern surgical techniques have shifted away from older methods called “vocal cord stripping” that removed large amounts of tissue. Current approaches focus on preserving as much healthy vocal fold tissue as possible to maintain voice quality^[12][19].

One preferred technique is the microflap technique, which preserves the superficial layer of the vocal fold while removing the abnormal tissue^[12][19]. Another method called “hydrodissection” involves injecting saline solution under the leukoplakia patch to lift it off the healthy tissue below, allowing removal with minimal tissue loss^[11].

Laser surgery may also be used. Angiolytic lasers, such as the pulsed dye laser and KTP laser, are well-designed for treating superficial disease on the vocal fold surface^[2][12]. These laser procedures may be performed in the operating room or, in some cases, in the doctor’s office in a minimally invasive fashion^[2][13].

After surgical removal, the tissue is always sent for laboratory analysis to determine whether dysplasia or cancer was present. Depending on these results, additional treatments such as repeated surgeries or further laser therapy may be necessary^[2].

Follow-Up Care

Regardless of which treatment approach is used, close follow-up is essential. Leukoplakia can recur even after successful treatment^[13]. Regular checkups with laryngoscopy allow the doctor to monitor for any return of white patches or development of new areas of concern.

For patients with a history of chronic laryngitis who develop repeated episodes of leukoplakia, regular control biopsies may be recommended even when the patches look similar to previous ones^[11]. The importance of continued tobacco and alcohol avoidance cannot be overstated, as these remain the primary risk factors for recurrence and progression to cancer.