I had a raised mole appear on my thigh a few years ago. It changed colors and had a weird shape to it. I would say most of the time it was a purple color but would change to a more brown color or sometimes even a lighter almost white color. I remember it would even bleed and bother me sometimes. Sometimes it was softer, but in the end it was hard. This mole thing stayed on my thigh for probably about 2 years..one day I noticed it was gone. Should I be concerned?