Ductal carcinoma in situ (DCIS or intraductal carcinoma) is a very
early form of noninvasive breast cancer that begins in the lining of the small
milk ducts that drain milk out of the breast through the nipple. It usually
does not cause a lump in the breast and is seen as small calcium deposits
(microcalcifications) on a mammogram.
Most experts consider DCIS a precancerous condition that may
progress to invasive breast cancer. Unfortunately, doctors do not know how to
tell which cases of ductal carcinoma in situ will progress and which will
Treatment options for DCIS include mastectomy or lumpectomy with
radiation. The medicine tamoxifen may be used to reduce the risk of future
How this information was developed to help you make better health decisions.