In leukoplakia of the oral mucosa (synonyms: Oral leukoplakia;Erythroplakia; Erythroplakia of oral cavity epithelium; Erythroleukoplakia; Gingival leukoplakia; Hairy leukoplakia; Idiopathic leukoplakia; Leukoplakia simplex; Oral cavity leukoplakia; Oral leukoplakia; Oral mucosal leukoplakia; Precancerous leukoplakia; Verrucous leukoplakia; Gum leukoplakia; Tongue leukoplakia; Candida-infected oral leukoplakia; ICD-10 K13. 2 Leukoplakia and other affections of the oral cavity epithelium, including tongue; ICD-10-GM K13.2: Leukoplakia and other affections of the oral cavity epithelium, including tongue) is a predominantly white change that cannot be characterized clinically or histopathologically as any other definable mucosal change.
Forms of the disease
Based on the clinical appearance, two variants are distinguished: the homogeneous form and the inhomogeneous form. Mixed forms are possible.
Special forms
In idiopathic leukoplakia there are no etiological (“causative”) factors.
Proliferative verrucous leukoplakia is an aggressive variant of oral leukoplakia, leading to malignant degeneration in almost all cases.
Sex ratio: In most countries, males develop the disease more frequently than females. However, this is not always true for the Western world.
Frequency peak: People between 40 and 70 years of age are considered at risk.
The prevalence (disease incidence) varies widely worldwide between 0.2 and 5% (India: 0.2 to 4%; Sweden: 3.6%; Holland: 1.4%). In Germany, the prevalence was found to be 2.3% for men and 0.9% for women.
Lifetime prevalence: The disease occurs more frequently in middle or older age.
Course and prognosis
Oral leukoplakia is the most common premalignant (potentially malignant) change of the oral mucosa. In principle, any oral leukoplakia can transform malignantly. Likewise, spontaneous regression is possible without specific therapy or by eliminating etiologic factors. The malignant transformation rate ranges from 0.9 to 17.5%. In the 5-year period, the transformation rate is 3 to 8% of all leukoplakias.
An increased risk of transformation applies to the following factors:
- Female disease
- Existing for a long time
- Occurrence in non-smokers
- Localization floor of the mouth or tongue
- Occurrence in patients with previous disease of squamous cell carcinoma of the head and neck region
- Inhomogeneous leukoplakia
- Candida-infected leukoplakia
- Epithelial dysplasia (deviation of tissue structure from the normal picture).
- DNA aneuploidy
Increased recurrence rates (rates of recurrence) are shown particularly by proliferative verrucous leukoplakia (PVL).The risk of transformation of PVL into squamous cell carcinoma is very high at 50% absolute and 9.3% per year. Also high is the risk of erythroplakia (reddish lesions): 33% absolute and 2.7% annual:For oral leukoplakia as a whole, the absolute rate was 8.8% and the annual rate was 1.6%.
Comorbidities (concomitant diseases):Oral hairy leukoplakia is pathognomonic (evidence of disease) for HIV. In Candida-infected oral leukoplakia (synonyms: Candida leukoplakia; hyperplastic candidiasis), it is unclear whether Candida infection is the cause of the leukoplakia or a superinfection of the altered mucosa.
