I agree you should get a follow up - i saw an ENT when I had a white patch on the bottom side of my tongue, who said it was just leukoplakia (an auto-immune thing) so I didn't worry about it. It came and went for a while, then eventually a red bump formed in the same area, which I really didn't even notice. When it started getting really painful I finally followed up about it a year later, and it was stage 3 - the oral surgeon i went to was able to diagnose me on the spot. I don't mean to scare you as in my ENT's defense it was highly unlikely for it to turn into cancer at my age; however, I have a lot of regrets to this day about not following up sooner. The cancer can grow very fast so the sooner the better!