I have a bean type thing under my scalp, been there for as long as i can remember. it feels smooth but is an awkward egg shape. It also has a yellow tint to it and is very hard and can be moved less than a mm. It always has a pinhole on it but nothing comes out when trying to squeeze it. If i mess with it it gives me a cold feeling in that side of my head. It hurts when i brush my hair. Any ideas?