What to do if i have painless white spot on palatopharyngeal arch?

Leukoplakia: You have shared no information with us especially if you smoke, your medical history or medications which makes it impossible to provide you a relevant differential diagnosis; however, what you are describing is suspicious for dysplasia or leukoplakia and may be neoplastic. This needs to be seen by ENT for eval and biopsy very soon. If you use nicotine stop.