Leukoplakia is best described as which of the following?

• A. White plaque which does not rub off and cannot be clinically identified
• B. White plaque that cannot be rubbed off
• C. Red patch in oral mucosa
• D. A salivary gland disorder

Answer: (A)

White patches on the oral mucosa that cannot be rubbed off and cannot be attributed to another condition describe leukoplakia. This is a diagnosis of exclusion: clinicians compare the lesion with other causes of white oral lesions (such as candidiasis, frictional keratosis from denture or teeth, lichen planus, chemical irritation, or tobacco-related keratosis) and only label it leukoplakia when no other diagnosis fits the appearance. The key is the persistent white plaque that cannot be wiped away, distinguishing it from conditions that can be scraped off like thrush. Leukoplakia can be present without symptoms but carries a risk of dysplasia or malignant change, so lesions with suspicious features or non-homogeneous appearance may be biopsied to assess risk. The red patch option describes erythroplakia, not leukoplakia, and a salivary gland disorder would present with gland-related signs rather than a fixed white patch.