Removal of Breast Tissue in the Armpit? (Photos)

it could be  breast tissue or fat or both.  I have only removed this tissue by liposuction.  I would reccommend use of laser assisted liposuction to get enhanced skin retraction.  Sometimes it may be best to go for reduction of the internal tissue not complete removal to avoid skin wrinkling or dimpling, discussing it with the client in advance, and including these issues in the consent form.  also may be wise to advise in advance that if wrinkling or dimpling occurs direct excision of skin and/or more tissue may become an option. 

Excess tissue can often be removed using liposuction alone, but that doesn't address the excess of skin that you may have (and appear to have in these photos).  It is either way a relatively small procedure; the scarring the results depends on which procedure is done.  You'll need to a see a board-certified plastic surgeon to get the answers to your other questions.  I hope that this helps and good luck, Dr. Alan Engler, Member of #RealSelf500