Recent studies show that certain types of microscopic changes that feature excessive cell growth or hyperplasia put a woman at higher risk of developing breast cancer. Approximately five percent of benign breast biopsies reveal both excessive cell growth (hyperplasia) plus cells that are abnormal (atypical). The location of these abnormal cells can be in the lobules (atypical lobular hyperplasia) or the milk ducts (atypical ductal hyperplasia).

If a biopsy finds hyperplasia, surgery can remove the abnormal cells and also determine if cancer is also present. Since atypical hyperplasia increases your risk of developing breast cancer, it is essential that you continue to monitor your breasts with regular mammograms and clinical breast exams. Depending on other risk factors such as family history, your doctor may also want to use magnetic resonance imaging for screening. Your doctor may suggest preventive medications to inhibit the effect of estrogen on your breast tissue.