My daughter has a light purple tinged lump on her leg, it is around 6cm long and half as wide, it has been there for many months now, the first diagnosis was a keloid, second diagnosis by a skin specialist a benign mole. Yesterday it appeared to break open and some yellowish pus came out followd by a watery discharge. Is this a normal thing for a mole to do, and is purple a common colour for a mole?