A patient presents with firm nodular growths on the lingual surface of the mandible, consistent with tori (exostosis). If a biopsy were performed on this lesion, what would be seen microscopically?

Correct answer: B. Normal mucosa overlying normal bone

• A. Dysplastic epithelial cells are characteristic of premalignant lesions such as leukoplakia or carcinoma in situ — not tori/exostoses, which are benign bony protuberances with no epithelial dysplasia.
• B. CORRECT. Exostoses (including tori) are benign focal overgrowths of cortical bone. Histologically, biopsy shows normal overlying mucosa (non-dysplastic stratified squamous epithelium) with normal underlying compact bone — no dysplasia, no inflammation, no unusual cellular activity. This benign appearance confirms the diagnosis.
• C. Inflammatory infiltrate with osteoclastic activity suggests active bone destruction seen in infections, osteonecrosis, or aggressive bone lesions — not present in benign exostoses.
• D. Calcification within fibrous connective tissue is characteristic of fibro-osseous lesions such as fibrous dysplasia or cemento-ossifying fibroma, not simple exostoses.