Lobular Neoplasia (Lobular Carcinoma In Situ)



  • Lobular: Relating to the breast lobule, the part of the breast that produces milk in a woman who has been recently pregnant or who is breast-feeding.
  • Carcinoma: A type of cancerous, or malignant, tumor.
  • Neoplasia: Any new or abnormal cell growth.
  • In Situ: In its original place.
  • Non-invasive: Not yet spreading to other parts of the breast or body.
  • Malignant: Cancerous and capable of spreading.
  • Pathologist: A physician who examines tissues and fluids to diagnose disease in order to assist in making treatment decisions. 

What is lobular carcinoma in situ (LCIS)?

Lobular carcinoma in situ, also known as lobular neoplasia, is not technically a cancer or a carcinoma. The alternate name for this condition–lobular neoplasia–is more technically accurate, since LCIS is only a “marker” of cancer in most women. In women who develop invasive lobular carcinoma, LCIS is a direct precursor.  An LCIS diagnosis means there is abnormal cell growth that increases your chances for developing breast cancer later in life. According to the National Cancer Institute, about 25 percent of women with LCIS develop invasive breast cancer within 25 years of the initial diagnosis. While having LCIS increases the chances of someday having breast cancer, most women with LCIS do not develop breast cancer. Due to improvements in breast cancer screening, the diagnosis of LCIS is increasing.

Who is most likely to have LCIS?

LCIS is more common in pre-menopausal women; however, LCIS can be found at any age.  About 20 percent of women with breast cancer have a family history of the disease. Other factors increasing the risk of having breast cancer include having no children or the first child after age 30, early menstruation, and consuming three or more alcoholic drinks a day.

What characterizes LCIS?

LCIS is characterized by the appearance of abnormal cells in the milk-producing lobules of the breast. LCIS rarely shows on a mammogram; instead, it is usually discovered by chance as part of a biopsy sample for a breast lump, which a pathologist examines.

How does the pathologist make a diagnosis?

The pathologist examines biopsy specimens, along with other tests if necessary. A biopsy is the most widely used method for detecting breast cancer. During a biopsy procedure, the primary care doctor removes cells or tissues from the suspicious area for the pathologist to examine more closely in the laboratory. In some cases, a biopsy may be performed with surgery. The pathologist also will note the size and location of the cell abnormalities. To make a firm diagnosis of LCIS, the pathologist will investigate whether the abnormal cells have invaded outside lobules into the surrounding tissue. A diagnosis of LCIS means the cell abnormalities remain only in their original place–“in situ.”

What else does the pathologist look for?

The biopsy sample is at this time not tested any further. All LCIS tumors are stage 0, which means the tumor is not cancerous. The cure rate for stage 0 tumors is close to 100 percent if standard forms of treatment are followed.

How do doctors determine what surgery or treatment will be necessary?

The pathologist consults with your primary care physician after reviewing the test results. Together, using their combined experience and knowledge, they determine treatment options most appropriate for your condition.

What kinds of treatments are available for LCIS?

Most women with LCIS do not receive immediate treatment; instead, they are closely monitored through regular clinical breast exams and mammography.  In addition, they are encouraged to do self-exams each month and to report unusual lumps or changes to a physician.

Some women with LCIS, usually those with a strong family history of breast cancer, choose the preventive removal of both breasts, a procedure known as prophylactic mastectomy, often followed with breast reconstruction. This treatment significantly reduces the risk of breast cancer.

Another option is to consider taking the drug tamoxifen, which was proved to reduce the risk of breast cancer in a recent clinical trial conducted by the National Surgical Adjuvant Breast and Bowel Project (NSABP). A second NSABP clinical trial, known as the STAR (Study of Tamoxifen and Raloxifene) trial, is now underway to compare the effectiveness of tamoxifen with raloxifene, a promising new anti-cancer drug. If you are interested, ask your physician about these drug therapy options.

For more information, go to (American Cancer Society) or

What kinds of questions should I ask my doctors?

Ask any question you want. There are no questions you should be reluctant to ask. Here are a few to consider:

  • Please describe the type of condition I have and what kind of preventive measures I can take.
  • Is any type of treatment recommended at this stage?
  • What are the pros and cons of these treatment options?
  • What are the side effects?
  • Should I receive a second opinion?
  • Is your medical team experienced in treating the condition I have?
  • Can you provide me with information about the physicians and others on the medical team?