Image of the Week: What's causing this distinctive mucosal pattern?

A 55-year-old woman presents with a three-month history of mouth pain, sensitivity to hot foods, and general oral discomfort. She mentions that her mouth sometimes bleeds after she brushes her teeth. On examination, white lace-like striations of the buccal mucosa are seen. Based on this patient's suspected diagnosis, which is the next most common site of involvement? Take the quiz, ...