I have a couple of small, hard which i ll refer to spots . One on my shoulder , another on my cafe,and a third on my armwhich started out almost like a pimple but reverted buy getting hard and Sitting right under skin. First I had the one on led, then shoulder and now arm only one is raised and the others are like have balls under skin. There really is no color and they come and stay the same size. So I guess I was wondering if these could be syst,or cancer