Definition

A condition in which cells that look somewhat abnormal under a microscope are found in the lining of a breast duct. The abnormal cells have not spread outside the duct to other tissues in the breast. Grade II ductal carcinoma in situ tends to grow more quickly than grade I ductal carcinoma in situ but not as quickly as grade III ductal carcinoma in situ. It is also more likely than grade I ductal carcinoma in situ to come back or become invasive breast cancer and spread to other tissues but not as likely as grade III ductal carcinoma in situ. Also called grade II DCIS, intermediate-grade DCIS, and intermediate-grade ductal carcinoma in situ.