question: I have lump, the size of a roma tomato, underneath my left breast. I showed it to my doctor last year in my yearly physical. She said it was probably a fatty tumor. Well this thing has grown and is feeling harder than last year. How big do these fatty tumors get and are they usually hard????Since I am being prompted to add my age, weight and such...here it goes. I am 44,five nine and 240 lbs. My medical history consists of high blood pressure since I was 24 and two c-sections. And this lump is under the breast, in the upper rib cage area, not in the breast. And yes I have had a mammogram, it showed nothing.