A 78-year-old man complains of a painful sore in his mouth that has been persisting for 2 months already. The patient is a smoker. Objectively on the buccal mucosa on the right there is a shallow ulcer up to 1.5 cm in size with lumpy ?oor and uneven margins. There are yellowish granules on its periphery. Palpation is painful, the lesion is soft. Regional lymph nodes are enlarged, painful, and matted together. What is the provisional diagnosis?