fibroadanoma

Hi, 15 years ago I had a lumpectomy, when I was 23 weeks pregnant the docs at that time told me it was a benign tumour they didn't describe it as a fibroadanoma. I am now 40 and 8 months ago had a misscarriage at 12 weeks, 2 months later I discovered a lump. I went for mammogram, then ultrasound and fine needle biopsy. Results came back as a fibroadanoma, size 26mm. Doc at that time told me not to worry and to come back 6 moths later for a ultrasound ti see if it had grown. I went back and was told it had grown so should have it removed, my breast is very painful at all times.  I have a history of breast and ovarian cancer in my family. Can fibroadanomas become malignant?

[Cleveland Clinic]

A fibroadenoma is a benign (non-cancerous) growth and is the most common benign tumor of the breast. The cause of fibroadenoma is not known.  Fibroadenoma may be a long-term risk factor for breast cancer depending on certain features such as complexity of the tumor.  
As long as the doctor is sure it is a fibroadenoma, there is no need to remove it, unless it is causing discomfort. In 50% of the cases fibroadenomas will go away on their own within 5 years. In others, the life of a fibroadenoma is about 15 years. In teenagers - the tendency is not to remove fibroadenomas. In middle age women, the tendency is to remove the fibroadenomas to be sure they are, in fact, fibroadenomas.