I am having a problem with insurance. As part of my routine dental visit, my dentist discovered a Erythroleukoplakia on the inside of my cheek.

I saw a DDS/MD who thought Ddx: Erythroleukoplakia Vs SCCa
- High suspicion for SCCa. I was then refereed to an oral cancer ENT / MD. My medical insurance carrier is denying all of the claims, CT, Biopsy and doctor visits because they say this is a dental claim and is excluded from my medical coverage. My dental policy has a very low maximum annual benefit. Is this right? Is all cancer a dental , not a medical issue? Do all oral cancer patient have to pay out of pocket?
Suggestions?