Carcinoma of the breast, infiltrating ductal means: Carcinoma, breast infiltrating, ductal: This is one of many types of breast cancers that are recognized. It begins in cells which form the ducts. This is the most prevalent form of breast cancer. Invasive ductal carcinoma can be seen on a mammogram as a large mass that radiates from the edges. Sometimes, it can be felt in the breast as a lump.
(in Medical Dictionary)