A couple of years ago i slipped on some rocks and badly bruised my leg and had a huge lump. it got better but there was always a slight bump there. the lump has become painful to touch and when walking it stiffens up and becomes painful.
often after we hurt ourselves or after surgeries scar tissue forms on that area. I cut my finger when I was 14; I still have a little bump due to scar tissue.This are always will be sensetive to touch.
But to be on safe side, just check it with your DR; not a bad idea.