Because of a lapse in government funding, the information on this website may not be up to date transactions submitted via the website may not be processed, and the agency may not be able to respond to inquiries until appropriations are enacted.

The NIH Clinical Center (the research hospital of NIH) is open. For more details about its operating status, please visit cc.nih.gov.

Updates regarding government operating status and resumption of normal operations can be found at USA.gov.

NCI Dictionary of Cancer Terms

  • Resize font
  • Print
  • Email
  • Facebook
  • Twitter
  • Google+
  • Pinterest

The NCI Dictionary of Cancer Terms features 8,188 terms related to cancer and medicine.

We offer a widget that you can add to your website to let users look up cancer-related terms. Get NCI’s Dictionary of Cancer Terms Widget.

Browse:
ductal carcinoma
(DUK-tul KAR-sih-NOH-muh)
The most common type of breast cancer. It begins in the lining of the milk ducts (thin tubes that carry milk from the lobules of the breast to the nipple). Ductal carcinoma may be either ductal carcinoma in situ (DCIS) or invasive ductal carcinoma. DCIS is a noninvasive condition in which abnormal cells are found in the lining of a breast duct and have not spread outside the duct to other tissues in the breast. In some cases, DCIS may become invasive cancer. In invasive ductal carcinoma, cancer has spread outside the breast duct to surrounding normal tissue. It can also spread through the blood and lymph systems to other parts of the body.