Sarina is 52 years old and presents with a 3 week history of pain underneath her right jaw line. She has noticed this come on soon after meals and that this area can sometimes feel swollen briefly also after eating. There is no history of dysphagia or weight loss. She had a recent sore throat and cold which has now settled and there is no history of cough. She is an ex-smoker.
On examination, observations are stable and you note a tender swelling in the right submandibular area.
What is the most likely diagnosis?