question: Hello.  I am 42 yrs old, 6'2", 172 lbs.  I have had this small pea size lump under the skin on my left bicep for years now.  I have noticed, as my bicep muscle has gotten smaller due to not working out as much anymore, that the small lump has begun to hurt when it is touched or rubbed on by my backpack strap or any other tight clothing etc.  It almost feels like there is a jagged edge to it and it is connected to my muscle somehow.  Thoughts?