Lobular Carcinoma in Situ (LCIS)

Lobular carcinoma in situ (LCIS) may also be called lobular neoplasia. In this breast change, cells that look like cancer cells are growing in the milk-producing glands of the breast (called the lobules), but they don’t grow through the wall of the lobules.

LCIS typically does not spread beyond the lobule (become invasive breast cancer) if it isn’t treated. But having LCIS increases your risk of developing an invasive breast cancer in either breast later on, so close follow-up is very important.


LCIS is diagnosed by a biopsy. (Breast tissue is removed and checked under a microscope.) Often, LCIS does not cause a tumor that can be felt or changes that can be seen on a mammogram.1 In most cases, LCIS is found when a biopsy is done for another breast problem that’s nearby.

You can learn more about pathology reports showing LCIS in Understanding Your Pathology Report: Lobular Carcinoma In Situ.


In most cases, LCIS does not need to be treated. Sometimes if LCIS is found using a needle biopsy, the doctor might recommend that it be removed completely (with an excisional biopsy or some other type of breast-conserving surgery) to help make sure that LCIS was the only thing there. This is especially true if the LCIS is described as pleomorphic or if it has necrosis (areas of dead cells), in which case it might be more likely to grow quickly .

Women with LCIS are at higher risk for breast cancer, so close follow-up with a health care provider is very important. This usually includes yearly mammograms and breast exams. Close follow-up of both breasts is important because women with LCIS have the same increased risk of developing cancer in both breasts. There isn’t enough evidence to recommend routine breast MRI in addition to mammograms for all women with LCIS, but it’s reasonable for women with LCIS to talk with their doctors about their other risk factors and the benefits and limits of being screened yearly with MRI.

Women should also talk to a health care provider about what they can do to help reduce their breast cancer risk.

Some women with LCIS choose to take medicine to help lower their risk of breast cancer. More details on this can be found in Deciding Whether to Use Medicine to Reduce Breast Cancer Risk.

Because LCIS is linked to an increased risk of cancer in both breasts, some higher risk women with LCIS (such as those with a strong family history of breast cancer or certain genetic changes) choose to have a bilateral prophylactic mastectomy (removal of both breasts but not lymph nodes) to help lower this risk. This may be followed by delayed breast reconstruction

How does LCIS affect breast cancer risk?

Women with LCIS have a 7 to 11 times higher risk of developing invasive cancer in either breast.2 For this reason, women with LCIS should make sure they have regular breast cancer screening tests and follow-up visits with a health care provider for the rest of their lives.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master’s-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Hartmann LC, Sellers TA, Frost MH, et al. Benign breast disease and the risk of breast cancer. N Engl J Med. 2005;353:229-237.

1 Kilbride KE, Newman LA. Lobular Carcinoma In Situ: Clinical Management. In: Harris JR, Lippman ME, Morrow M, Osborne CK, eds. Diseases of the Breast. 4th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2010:341-347.

National Cancer Institute. Understanding Breast Changes: A Health Guide for Women. April 23, 2015. Accessed at www.cancer.gov/types/breast/understanding-breast-changes on June 10, 2016.

National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology. Breast Cancer. Version 2.2016. Accessed at www.nccn.org/professionals/physician_gls/f_guidelines.asp on June 10, 2016.

National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology. Breast Cancer Risk Reduction. Version 1.2016. Accessed at www.nccn.org/professionals/physician_gls/pdf/breast_risk.pdf on June 10, 2016.

2 Obeng-Gyasi S, Ong C, Hwang ES. Contemporary management of ductal carcinoma in situ and lobular carcinoma in situ. Chin Clin Oncol. 2016 May 11. [Epub ahead of print]

Renshaw AA, Gould EW. Long term clinical follow-up of atypical ductal hyperplasia and lobular carcinoma in situ in breast core needle biopsies. Pathology. 2016;48:25-29.

Last Medical Review: March 16, 2015 Last Revised: April 21, 2016



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