What Is The Treatment For White Circle In The Vaginal Lip?

I have a nickel sizrd white circle just on the inside of my vagina lip that is ridged and is itchy, but looks very ominus (scary) it is only ONE white circle and the inside of it looks indented. Can you please maybe rell me some info about it? I have an appointmet with my personal doctor in 2 days for this. Please help answer this for me as ti ....could it possibly be cancerous, and is there any photos that I can see that might look like what I have?