A suspicious mucosal lesion measuring 3 cm requires definitive diagnosis. What is the MOST appropriate next step?

Correct answer: A. Incisional biopsy including a margin of adjacent normal tissue

• A. CORRECT. INCISIONAL biopsy is indicated for lesions that are LARGE (generally greater than 1 cm), clinically suspicious for malignancy, diffuse, or located where wide excision would cause avoidable morbidity. Taking a representative wedge that spans the lesion edge and includes adjacent normal tissue lets the pathologist judge the interface. Establishing the diagnosis FIRST allows definitive surgery to be planned with appropriate margins by the appropriate surgeon.
• B. Excisional biopsy is appropriate for SMALL (under 1 cm), clinically benign-appearing lesions such as a fibroma or mucocele, where removal is both diagnostic and curative. Excising a 3 cm suspicious lesion without a diagnosis risks an inadequate margin and compromises definitive management.
• C. Radiographs assess bone, not soft tissue, and cannot provide a histological diagnosis.
• D. Exfoliative cytology samples only surface cells and cannot demonstrate invasion through the basement membrane — the very finding that defines malignancy. A negative result cannot exclude carcinoma, so it is an adjunct, never a substitute for biopsy.

Note: Biopsy technique points: sample the most suspicious area, avoid the necrotic center, include the lesion–normal interface, do not inject anesthetic directly into the specimen, and never use electrosurgery on the sample (thermal artifact destroys the histology).