Ductal carcinoma in situ. Malignant epithelial proliferation occupying duct spaces but confined within the basement membrane. It is a heterogeneous entity, radiologically, pathologically and biologically.
DCIS stands for ductal carcinoma in situ. DCIS is an early form of breast cancer that starts in the milk ducts. See breast cancer section.
Abnormal cells that involve only the lining of a duct and have not spread outside the duct to other tissues in the breast. Also called DCIS or intraductal carcinoma.