I am a 24 year old with a vascular birthmark.
I would suggest maybe get another opinion from one of the doctors listed in your area that are in the resource section at the top of this page, or email Dr. Levintin who is the Ask the sergeon doctor on the home page of this website. He works with my plastic sergeon Dr. Waner. They both treat AVMs, AM, and mostly hemangiomas. I take pictures and email them to him in your email asking him what he thinks you should do.
My personal opinion would be to get it removed. But the question is could it come back and that really depends on what exactly it is.
Hope this helps.