With atypical ductal hyperplasia (ADH), there are more cells than usual in the lining of the breast duct, the tube that carries milk from the lobules (milk sacs) to the nipple. These cells share some, but not all, of the features of low-grade ductal carcinoma in situ (DCIS), both in terms of growth patterns and appearance. ADH is a benign breast condition linked to a moderate increase in breast cancer risk.
If you have a core needle biopsy that discovers atypical cells, your doctor likely will go on to remove more of the tissue in that area. Since ADH is not a true cancer, though, there can be some variation in how doctors approach them. Some doctors feel there is no need for additional surgery after the initial biopsy. Decisions about removal have to be made on a case-by-case basis. You and your doctor can work together to make the best choice for you.
With ADH, you may wish to seek a second opinion, asking another pathologist to review the tissue samples. This might reassure you that this is atypical hyperplasia and not an early form of breast cancer.
Whatever your situation, it makes sense to be followed by a doctor with expertise in breast health. Generally, a follow-up physical exam is done at 6 months and a mammogram may be recommended. After that, most women can resume yearly mammograms; in selected cases, doctors may add breast MRI.
For some women, doctors may suggest a hormonal therapy such as tamoxifen, raloxifene, or an aromatase inhibitor to reduce their risk of breast cancer. Studies have found that most ADH cells test positive for estrogen and progesterone receptors. These treatments have side effects, though, so your individual situation will determine whether their benefits outweigh their risks.
For more information, see Follow-up Care for Benign Breast Conditions.