What does a cancerous skin tag around the mouth look like?

I have a 6yr old female mixed breed that has a couple of skin tags and I know they are nothing to worry about, generally... So last night I googled when they are something to worry about and kept finding when they are on or around the mouth. Kelsie has 1 on her lip that has been there and slowly growing for just over a year now. I brought it to the vets attention last year and said it was fine, didn't recommend taking it off, even while they had her out for a teeth cleaning.
This year, a different doc again suggested the teeth cleaning and said they would take it off at that time. He didn't sound concerned, but it just kept bothering me, which is when I googled it.

Can anyone tell me anything? What does a cancerous skin tag on the mouth look like? I do have pictures. I have an apt with a trusted friend's vet on Wednesday, but just wanting to be prepared or some peace of mind!

Thank you for your help!! =)

Asked by Member 1128644 on Aug 31st 2012 Tagged skintags, cancerousskintags, lipskintags in Skin Problems