I have had several experiences like the one mention. I am 28 and had my first lump about 2 years ago. It was on the side of my breast and was warm to the touch. After a few days it got bigger, it never came to a head but just like a pore opened and began to leak pus. I had that happen 4 time in the year to follow and was eventually told that caffine can cause cysts like this. I gave up caffine and have not had one since.