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 DCIS tends to grow more quickly than grade I DCIS but not as quickly as grade III DCIS. It is also more likely than grade I DCIS to come back or become invasive breast cancer and spread to other tissues but not as likely as grade III DCIS. Also called grade II ductal carcinoma in situ, intermediate-grade DCIS, and intermediate-grade ductal carcinoma in situ.