What is lobular carcinoma in situ (LCIS)?

Lobular carcinoma in situ (LCIS) is the name for abnormal cells that are contained in the lobules of the breast. The causes of LCIS are unknown.

What’s the difference between LCIS and invasive breast cancer?

In LCIS, the abnormal cells stay inside the lobules of the breast and do not spread to other parts of the breast or body. A woman cannot die from having only LCIS.

What are the symptoms of LCIS?

LCIS cannot usually be felt as a breast lump or other breast change. Changes due to LCIS only sometimes show up on a mammogram.

Most cases of LCIS are found when a woman has a biopsy for another reason. Most women are not aware of any symptoms at the time of diagnosis.

Does LCIS need to be treated?

LCIS is not the same as invasive breast cancer. LCIS does not need to be treated if there are no other abnormal changes to the breast. However, having LCIS increases the risk of developing breast cancer.

If a woman has LCIS, it’s important that she has regular check-ups, including:

  • a physical examination of both breasts by a doctor once a year
  • a mammogram/ultrasound of both breasts once a year.