K.S.
My 2 month old daughter was born with one on the back of her scalp. It moves a little when you rub the skin. The pediatrician said it was indeed a cyst and that it would either go away on its own, or stay that same pea-sized shape as she grew bigger. She says its not a cause of concern and that it shouldn't cause pain. But I have on on my left wrist that appeared when I was a teen and I know from experience that if I bump my hand it will hurt, or if I press on it, its hurts a bit. They are liquid filled and can be drained or completely removed. Had mine removed at 16 and it came back within a year or two- so I let it be. When my daughter gets old enough to talk I'll know if it bothers her as far as pain. If it doesn't and since its covered by her hair, I'll probably leave it alone. Good luck.