History of the present illness

This is a 53-year-old white female referred by her dentist for the evaluation of a 4 x 3 mm flat, well-demarcated pigmented lesion on the right anterior floor of mouth (Figure 1). The lesion was of unknown duration and was asymptomatic. The patient stated, "I had no idea it was there until my dentist noticed it." Clinically, the lesion was brown to blue/black in color. Her past medical history is significant for a hysterectomy 7 years previously. She has no history of tobacco use. The patient has no current medical problems, no medications and no allergies.

Figure 1 Clinical photograph of the lesion taken at the first visit. Note the flat, well-demarcated, dark brown lesion on the right anterior floor of mouth.