Liz
Like you knowing that you recently had a scan I'm not unduley worried about you (well I am but I'm not letting you know that). I've had an area for lukoplasia along my scar tissues for a long time and no-one seems worried, so as Mike sujests is you are chewing on that bit of gum it could just be trauma. Try some Difflam mouthwash abour

SCC Base of tongue, (TISN0M0) laser surgery, 10/01 and 05/03 no clear margins. Radial free flap graft to tonsil pillar, partial glossectomy, left neck dissection 08/04