I had surgery a week and a half ago to remove Lymph nodes from my right arm pit. I have soreness all the way down my arm, kind of feels like its bruised, but no visible bruising down my arm. I also have a half dollar size hard knot under my armpit, around the stitches, that is very painful, what could that be and what do I need to be concerned about???? The surgeon took out 10-12 lymph nodes that came back benign, thank goodness.