No TZ zone

Hi ive had 2 biopsys now that have shown no TZ zone, i have cervical ectopy and minimal acetowhite changes and the squadmolecular junction was visable what does this mean? My colposcopist has referred me for cold coag treatment but if no TZ zone was visable shouldnt i be having a Lletz instead? I have no HPV and have had treatment over 10 years ago for CIN 1 (cold coag & Lletz) please someone advise