I have several small moles (2-3 mm) on my neck which are slightly prominent. They've been there and stable for years - I had a larger one removed when I was 14 but they left the little ones. Over the last week or so one of them started to get a bit bigger and began to be sore to the touch. Today I was absently scratching my neck and something hard and brown dropped into my fingers. When I went to the mirror I realised it was the sore mole that had dried up and spontaneously dropped off. There is a red mark where it used to be. Should I be worried? Has this ever happened to anyone else? I don't want to bother my doctor over something trivial, but they do say to keep a eye on your moles if they change - and drying up and dropping off is defiitely a change.