L

Lobe: A portion of an organ, such as the liver, lung, breast, thyroid or brain.

Lobular Carcinoma in Situ: LCIS is abnormal cells found in the lobules of the breast. This condition seldom becomes invasive cancer; however, having LCIS in one breast increases the risk of developing breast cancer in either breast.

Lobule: A small lobe or a subdivision of a lobe.

Local Therapy: Treatment that affects cells in the tumor and the area close to it.

Locally Advanced Cancer: Cancer that has spread only to nearby tissues or lymph nodes.

Lumpectomy: Surgery to remove the tumor and a small amount of normal tissue around it.

Lymph: The clear fluid that travels through the lymphatic system and carries cells that help fight infections and other diseases. Also called lymphatic fluid.

Lymph Node: A rounded mass of lymphatic tissue that is surrounded by a capsule of connective tissue. Lymph nodes filter lymph (lymphatic fluid), and they store lymphocytes (white blood cells). They are located along lymphatic vessels. Also called a lymph gland.

Lymph Vessels: Thin tubes that carry lymph (lymphatic fluid) and white blood cells through the lymphatic system. Also called lymphatic vessels.

Lymphatic System: The tissues and organs that produce, store, and carry white blood cells that fight infections and other diseases. This system includes the bone marrow, spleen, thymus, lymph nodes, and lymphatic vessels (a network of thin tubes that carry lymph and white blood cells). Lymphatic vessels branch, like blood vessels, into all the tissues of the body.

Lymphedema: A condition in which excess fluid collects in tissues and causes swelling. It may occur in the arm or leg after lymph vessels or lymph nodes in the underarm or groin are removed or treated with radiation.

M

Magnetic Resonance Imaging: MRI. A procedure in which a magnet linked to a computer is used to create detailed pictures of areas inside the body. Also called nuclear magnetic resonance imaging.

Malignant: Cancerous. Malignant tumors can invade and destroy nearby tissue and spread to other parts of the body.

Mammogram: An x-ray o the breast.

Mastectomy: Surgery to remove the breast (or as much of the breast tissue as possible).

Menopausal Hormone Therapy: Hormones (estrogen, progesterone, or both) given to women after menopause to replace the estrogen no longer produced by the ovaries. Also called hormone replacement therapy.

Menopause: The time of life when a woman’s menstrual periods stop permanently. Also called “change of life”.

Menstrual Cycle: The monthly cycle of hormonal changes from the beginning of menstrual period to the beginning of the next.

Menstruation: Periodic discharge of blood and tissue from the uterus. From puberty until menopause, menstruation occurs about every 28 days when a woman is not pregnant.

Metastasis: The spread of cancer from one part of the body to another. A tumor formed from cells that have spread is called a “metastatic tumor” or a “metastasis”. The metastatic tumor contains cells that are like those in the original (primary) tumor. The plural form of metastasis is metastases.

Metastasize: To spread from one part of the body to another. When cancer cells metastasize and form secondary tumors, the cells in the metastatic tumor are like those in the original (primary) tumor.

Microcalcifications: Tiny deposits of calcium in the breast that cannot be felt but can be detected on a mammogram. A cluster of these very small specks of calcium may indicate that cancer is present.

Modified Radical Mastectomy: Surgery for breast cancer in which the breast, most or all of the lymph nodes under the arm, and the lining over the chest muscles are removed. Sometimes the surgeon also removes part of the chest wall muscles.

Monoclonal Antibodies: Laboratory produced substances that can locate and bind to cancer cells wherever they are in the body. Many monoclonal antibodies are used in cancer detection or therapy; each one recognizes a different protein on certain cancer cells. Monoclonal antibodies can be used alone, or they can be used to deliver drugs, toxins, or radioactive material directly to a tumor.

N

Needle-localized Biopsy: Using very thin needles or guidewires to mark the location of an abnormal area of tissue so it can be surgically removed. The doctor uses an imaging device to place the wire in or around the abnormal area. Needle localization is used when the doctor cannot feel the mass of abnormal tissue.

Neoadjuvant Therapy: Treatment given before the primary treatment. Examples of neoadjuvant therapy include chemotherapy, radiation therapy, or hormone therapy.

Nipple: The small raised area in the center of the breast through which milk flows to the outside.

Nipple Discharge: Fluid coming from the nipple.

Dictionary

A-BC-D-EF-G-H-I-J-KL-M-NO-P-QR-S-TU-V-W-X-Y-Z

Please note that the above definitions were taken from the NCI (National Cancer Institute) booklet, What You Need to Know About Breast Cancer.