I am a 37 year old male, and i have noticed a few small, soft lumps on my left pectoral muscle, on the outside part near, but not at, my armpit. They are located at the bottom of the fleshy part of my outer pec, near the bottom. they don t hurt, but they are slightly irritating. sometimes it acutely hurts when i pull my left arm across my chest to my right arm. Any guesses as to what is going on?