Reoccurance concern - strange mass

I finished treatnment for Stage IV IBC last November and feel great.  A few weeks ago I noticed some small purplish blood vessels on my side, then saw and felt a "puffy" area all around it.  It is on the bottom of my ribcage area, just under where my breast was ,on the left side which was the side of my IBC.  It is about the size of my palm, and sticks out noticeably as compared to the other side.

 There are no visable signs of skin mets.  I'm wondering if anyone has had this type of swelling?  It is not lymph nodes - and not due to any know injury.  It's just wierd.  It feels somewhat like the mass I had with IBC.  I am going in for a biopsy Tuesday, but just would like to know if anyone has had anything similar.   Thanks!