It is most probably a benign lesion called fibroadenoma or breast mouse. But nothing can be said with certainty without a proper clinical evaluation. Schedule an appointment with your physician and see what he has to say and whether any intervention needs to be done for it. Goodluck.
my 27 year old daughter discovered 4 lumps in her breasts when she had a physical. needle biopsy on Monday, but today, Saturday, a lump appeared in her armpit. Any ideas