I have the same exact problem! I think some type of cyst. I have also gotten them on my face and ears. I have one removed from my face, one from my eyelid. I got on about a year and a half ago under my boob. It went from quarter size to the size of a large lemon over night. Not even kidding. The draining process was quite painful, and i had to pack it with these cloth strips, and had to to Wound care at the hospital every week for over a month. Ive decided to suffer with the ones that pop up downstairs for fear of the pain to remove them, and the pure embarassment. I wish i was more help.