I have had a lump in my right breast for over 2 years. I have seen a doctor annually but none of them have said anything about it until I started going in for prenatal check ups. I've had fibroadenomias in the past but they don't get much bigger than 2 or 3 cm and don't normally get bigger. In the last 1 1/2 years my lump has doubled in size. Does it sound like this lump could be malignant?