A Rapidly Enlarging Pigmented Lesion of the Buccal Mucosa

pigmented lesion
The following Case Challenge is provided in conjunction with the American Academy of Oral and Maxillofacial Pathology.

A 39-year old African American male noticed the presence of a brown, slightly rough lesion on the inside of his left cheek. It was asymptomatic and was discovered by the patient three weeks ago. He could not recall a history of trauma, such as cheek biting, undue force to the side of his face, or any recent dental treatment. He was unaware if the lesion had changed size or color during the several weeks prior to presentation.

After you have finished reviewing the available diagnostic information, make the diagnosis.