A pipe smoker is found to have a white, elevated plaque on his buccal mucosa during a general medical examination. The area cannot be wiped away with sterile gauze. What is the most likely diagnosis?

Leukoplakia is a precancerous lesion that appears as a white, elevated, plaque-like growth. It usually has asymmetric borders and usually affects the oral mucosa. It cannot be wiped off. The lesions tend to occur on the lip, mouth, buccal mucosa, and vaginal mucosa. Those at risk are cigarette smokers, pipe smokers, smokeless tobacco users, and heavy alcohol users. Others at risk include those with chronic oral infections, chronic malocclusion, or chronic ultraviolet light exposure. If suspected, these lesions should be biopsied to rule out malignancy. Approximately 10% may show malignant transformation. Candida infections can resemble leukoplakia, but candida can be removed using a cotton swab.