Breast pain was my first symptom of IBC, but it didn't stay my only symptom for long.  Within a month, my breast was puffy and pink.  Within six weeks I had developed the orange peel dimpling so typical of IBC.  The discoloration went from pink to dark red/purple overnight.  There is a wide variation in how people present with IBC.  I would never tell someone that her symptoms could not be IBC.   However, IBC symptoms usually get worse very quickly.  My six-week progression was unusually slow.  Although a biopsy might rule out IBC, it would create scar tissue that would possibly increase your pain.  I personally would be reluctant to have a biopsy with symptoms that are so different from typical IBC.  Perhaps a fine needle biopsy could sample both skin and breast tissue in several spots, but without the visible symptoms that characterize IBC, the doctor might have trouble finding the right places to biopsy.  A negative biopsy still would not be proof that you didn't have IBC because you would not know for sure if the biopsy hit the right spots.  You definitely need to follow-up on why your left arm is numb and tingly.  That could be a nerve related problem.  As PJ mentions, problems in the left chest and arm can also be cardiac related.  I believe you told me earlier that you have been checked for cardiac problems, but stay in touch with your doctor if your symptoms get worse.