Hemangioma or Port Wine Stain?

Lyla was born with a birthmark running from her hand and the entire length of her forearm. The pediatrician called it a Hemangioma which eventually fades with time. She sent us to a demotologist who said it was a Port Wine Stain which is permanent and thickens with time and can form lumps but can be removed with laser surgery. She sent us to a specialist at UCI who can't decide which one it is & wants to do an MRI to figure it out. We've decided to hold off on the MRI (she'll have to be put down) until January so until then, when someone asks me what she's got on her arm I'll say "Uh, I dunno..." It's not something that bothers us at all, only a super rude comment that I won't mention. But if it's a port wine stain we'll almost certainly have it removed because if we don't I'm sure she'll hate us for it when she's older :)