A 58-year-old man treated with chemoradiotherapy for squamous cell carcinoma of the tonsil presents at follow-up with pain in the back of his mouth. What is the most likely diagnosis?
A 58-year-old man receives chemoradiotherapy as definitive management for a T3, N2b squamous cell carcinoma of the tonsil. He returns to clinic for a 6-week post-treatment follow-up visit, complaining of pain in the back of his mouth. Transoral exam is notable for the following finding (red arrow).
What is the most likely diagnosis?