How is ductal carcinoma in situ (DCIS) diagnosed?

The sooner this type of cancer is found, the sooner it can be treated. The following tests or procedures are usually used to diagnose DCIS:

  • Breast examination: A routine breast exam is usually part of a regular physical. It is the first step in detecting breast cancer. Although DCIS does not usually come with a noticeable lump, the doctor may be able to feel an abnormal growth in the breast, such as a small, hardened spot, during a physical examination. The doctor will also look for any skin changes, nipple changes or nipple discharge. Most times, though, the abnormal growth will show up on a mammogram.
  • Mammogram: DCIS is usually found during a mammogram. As old cells die off and pile up within the milk duct, they leave tiny, hardened calcium spots which show up as a shadow or white spot on a mammogram.
  • Biopsy: If a spot or a shadow is found on the mammogram, the doctor will recommend a biopsy.
  • Core needle biopsy: With this procedure, the doctor inserts a large needle into the breast to get a big sample of the breast tissue that looked abnormal on the mammogram. The doctor will first numb the skin at the site of the biopsy and then make a small incision in the skin to help get the needle into the breast. Because the skin has been cut, there will be a tiny scar which will fade over time.

If a needle biopsy does not get enough breast cells or tissue to properly examine, or the results are not clear cut, the doctor may suggest another biopsy.
The following procedures are considered surgery:

  • Incisional biopsy: Through an incision, or a cut in the skin, the doctor can remove a sample of breast tissue to examine it further.
  • Excisional biopsy: This procedure cuts out the entire lump of tissue from the breast.

Biopsies are only used to diagnose that there is cancer within the breast. If cancer is found, surgery will be recommended to remove the abnormal cells.

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