Biopsy is indicated for the assessment of any unexplained oral mucosal abnormality that persists despite treatment or the removal of local irritants. Malignancy is suspected when persistent oral mucosal lesions are red or red and white or when they are ulcerated, indurated, or fixed to deeper tissues. Persistent lesions that bleed easily or grow rapidly should also alert the clinician to the possibility of malignancy. Unexplained pigmented oral lesions are of concern if they are new or changed. Biopsy is recommended unless the pigmented area has been present and unchanged for 5 years or longer.
Scalpel biopsy may be warranted even when the differential diagnosis includes only benign entities. Lesions that interfere with function and those that have an undesirable effect on esthetics should be excised.
Even experienced clinicians have difficulty in distinguishing between truly innocuous oral mucosal changes and those that represent dysplasia or early invasive cancer. Therefore, the decision to forego biopsy in an apparently benign lesion should be made with great care and only when the patient understands the need for close follow-up and agrees to comply.