Overview
Lobular carcinoma in situ is a growth of cells that happens in a milk gland in the breast tissue. The cells undergo changes that make them look different from typical cells. Lobular carcinoma in situ, which is often shortened to LCIS, isn't cancer. But having lobular carcinoma in situ increases the risk of getting breast cancer in the future.
Lobular carcinoma in situ usually isn't found on a mammogram or felt during a breast exam. The condition is most often found after a procedure to remove some breast tissue, such as a breast biopsy or a lumpectomy.
Lobular carcinoma in situ increases the risk of breast cancer in both breasts. If you're diagnosed with lobular carcinoma in situ, you may need increased breast cancer screening. You also may want to consider treatments to reduce your risk of developing invasive breast cancer.
Lobular carcinoma in situ
Lobular carcinoma in situ is a growth of cells that happens inside a milk gland, also called a lobule, in the breast. Lobular carcinoma in situ, also called LCIS, isn't cancer. It's a sign of an increased risk of breast cancer.
Symptoms
Lobular carcinoma in situ doesn't cause signs or symptoms. It's usually found after a procedure to remove some breast tissue, such as a breast biopsy or a lumpectomy. Lobular carcinoma in situ, also called LCIS, isn't cancer. It's a sign that you have an increased risk of breast cancer in the future.
When to see a doctor
Make an appointment with a doctor or other healthcare professional if you notice a change in your breasts. Changes may include a lump, an area of puckered or otherwise unusual skin, a thickened region under the skin, and nipple discharge.
Ask when you should consider breast cancer screening and how often it should be repeated. Most healthcare professionals recommend routine breast cancer screening beginning in your 40s.
Causes
It's not clear what causes lobular carcinoma in situ, also called LCIS. Lobular carcinoma in situ begins when cells in a milk-producing gland of a breast, called a lobule, develop changes in their DNA. These changes cause the cells to look different from healthy cells. The changed cells remain in the lobule and don't extend into, or invade, nearby breast tissue.
If you have lobular carcinoma in situ, it doesn't mean that you have cancer. But having lobular carcinoma in situ increases your risk of breast cancer and makes it more likely that you may develop invasive breast cancer.
The risk of breast cancer in women diagnosed with lobular carcinoma in situ is thought to be approximately 25% to 30%. For comparison, the risk of developing breast cancer for women in general is thought to be 13%.
Your individual risk of breast cancer is based on many factors. Talk to your healthcare team to better understand your personal risk of breast cancer.
Breast anatomy
Each breast contains 15 to 20 lobes of glandular tissue, arranged like the petals of a daisy. The lobes are further divided into smaller lobules that produce milk for breastfeeding. Small tubes (ducts) conduct the milk to a reservoir that lies just beneath your nipple.
