Ductal carcinoma in situ (DCIS)

Ductal carcinoma in situ (DCIS) is the presence of abnormal cells inside a milk duct in the breast.

DCIS is considered the earliest form of breast cancer. DCIS is noninvasive, meaning it hasn't spread out of the milk duct to invade other parts of the breast.

DCIS is usually found during a mammogram done as part of breast cancer screening or when there is another concern with a woman's breast. Because of increased screening with mammograms, the rate at which DCIS is diagnosed has increased dramatically in recent years.

While DCIS isn't life-threatening, it does require treatment to prevent the condition from becoming invasive. Most women with DCIS are effectively treated with breast-conserving surgery and radiation.

Symptoms Causes Risk factors

DCIS doesn't cause any signs or symptoms in most cases. However, DCIS can sometimes cause signs and symptoms, such as:

  • A breast lump
  • Bloody nipple discharge

DCIS is usually found on a mammogram and appears as small clusters of calcifications that have irregular shapes and sizes.

When to see a doctor

Make an appointment with your doctor if you notice a change in your breasts, such as a lump, an area of puckered or otherwise unusual skin, a thickened region under the skin, or nipple discharge. Contact your doctor to have it evaluated.

Ask your doctor when you should consider breast cancer screening and how often it should be repeated. Most groups recommend routine breast cancer screening beginning in your 40s. Talk with your doctor about what's right for you.

© 1998-2015 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. Terms of use