A smokeless tobacco user has a suspicious white lesion on the lateral border of the tongue. Which diagnosis MUST be included in the differential?

Correct answer: B. Squamous cell carcinoma

• A. Incorrect. Geographic tongue presents as irregular depapillation with white borders on the DORSUM — not a fixed lateral tongue white lesion.
• B. Correct. A suspicious white lesion on the LATERAL TONGUE in a smokeless tobacco user MUST include squamous cell carcinoma (SCC). The lateral/ventral tongue is the highest-risk site for oral SCC. Smokeless tobacco is a known carcinogen. Biopsy is required.
• C. Incorrect. Nicotinic stomatitis affects pipe/cigar smokers and appears on the HARD PALATE — not the lateral tongue.
• D. Incorrect. Denture stomatitis occurs under a prosthesis on the palate — not on the lateral tongue.