For the last 10+ years (I am 22). I have had a moveable ball on my jaw line to the right of my chin. I was told as a kid that it was probably a cyst and never thought anything of it. Every now and again (maybe once a year if that) it may be a bit tender when I move it. It's a perfectly round ball which is solid and is probably a bit bigger than a pea. Should I be worried? (It has never changed shape or size and is in the exact same place I always remember it. It's not visible on the outside of my skin, it is just something I can feel when I try to find it).