A patient presents with thick, non-scrapable white lesions in the mouth. What is the most appropriate next step?

• A. Nystatin rinse
• B. Cryotherapy
• C. Biopsy
• D. Nothing

Answer: (C)

Thick, non-scrapable white plaques in the mouth are suspicious for premalignant or malignant processes such as leukoplakia or erythroplakia. These conditions can harbor dysplasia or early cancer, so obtaining a biopsy is the essential next step to establish diagnosis and guide treatment. Antifungal therapy would not help here because the lesion isn’t Candida-related, which often presents as scrapable or responds to antifungals. Treating with cryotherapy isn’t appropriate for an unknown white plaque since it doesn’t provide diagnostic information and could delay cancer detection. Doing nothing risks missing a potentially serious diagnosis. If the biopsy shows leukoplakia with dysplasia, management involves removal or close surveillance; if larger or invasive changes are found, referral for appropriate cancer treatment is needed.