Very worried lump close to scar of mastectomy

Hi there, I agree with everyone about the probability of it being scar tissue but here is what happened to me!.  I also found a lump near the center of my breast right underneath my scar and completely freaked out thinking the worst.  I made an appointment and when my surgeon had a feel she smiled and say you will not believe what I am about to tell you but please stop worrying.  Turned out with some silicone implants (like mine) they have this small bump in the implant where the manufacturers have sealed the implant off.  There are actually two tiny manufacturer bumps on each implant.  She made me feel the other breast and whallah!  same thing on that side.  She then did an ultrasound anyway to just give me peace of mind.:)
It gave me the biggest fright ever!  but the only relief we ever get is when we have these things checked.  Just don't assume the worst cause it can definitely be scar tissue or even a small silicone bump from your implant.  I have scar tissue as well which also freaked me out when I became aware of it.  I am sure yours will be too.