Labia (sing labium) - Lips or something resembling lips, as in the folds of skin enclosing the vulva (the labia majora and minora).
Labour - The process of giving birth, from dilatation of the cervix to expulsion of the afterbirth. It usually commences naturally, although some labours are induced. On average, labour lasts 12 hours (less for subsequent pregnancies).
Lactation - The process of milk secretion by the mammary glands in the breast, which begins at the end of pregnancy. Colostrum is produced and secreted before the milk. Lactation is controlled by hormones and stops when the baby ceases to be breast fed.
Lanugos - A fine, downy hair. It covers the foetus between the fifth and ninth months and is lost in the ninth month so is seen only on babies born prematurely. It is also a symptom of severe anorexia nervosa.
Latissimus dorsi muscle - Triangular back muscle that is transferred with some overlying skin as donor flap tissue for reconstructing a breast after mastectomy.
Lesion - An area of tissue that is diseased.
Leucorrhoea - A discharge of white or yellow-coloured mucus from the vagina. It may be a normal condition, increasing before and after menstruation, but a large discharge probably indicates an infection somewhere in the genital tract. A common cause is the infection called thrush but it may also be a result of gonorrhoea, in which case the treatment will differ.
Libido - The sexual drive often associated with psychiatric illnesses. Lack of libido may be the result of illness or a lack of sex hormones because of an endocrine disorder.
Lightening - A sensation experienced by many pregnant women, normally towards the last month of the pregnancy, when the foetus settles lower in the pelvis. This lessens the pressure on the diaphragm and breathing becomes easier.
Lobular - Pertaining to the part of the breast that is furthest from the nipple, the end portion of the lobes.
Lobular carcinoma in situ (LCIS) - A change in the breast lobule that increases risk of breast cancer. It is a marker for breast cancer.
Lobular cell - A cell in the lobule of the breast; used for making milk.
Local control - The control of cancer in the breast.
Local recurrence - The return of cancerous cells to the breast.
Local treatment of cancer - Treatment only of the tumour.
Localized cancer - Cancer confined to its site of origin.
Lumen - The space within a tube, vein, or artery.
Lump - Any kind of abnormal mass in the breast or elsewhere in the body. May be malignant or benign.
Lumpectomy - Surgical removal of a cancerous tumour along with a small margin of surrounding tissue,
Lymph - A dear fluid that circulates throughout the body in the lymphatic system; contains white blood cells and antibodies.
Lymph Gland - Also called a lymph node. These are round-bodied tissues in the lymphatic system that vary in size from a pinhead to an olive and may appear alone or in groups. The principal ones are in the neck, underarm and groin. These glands produce lymphocytes and monocytes (white blood cells which fight foreign substances) and serve as filters to prevent bacteria from entering the bloodstream. They will filter out cancer cells but will also serve as a site for metastatic disease. The major ones serving the breast are in the armpit..Some are located above and below the collarbone and some in between the ribs near the breastbone. There are three levels of lymph nodes in the underarm area of the breast and another one around the breast bone. The number of nodes varies from person to person. Lymph nodes are usually sampled during surgery to determine if the cancer has spread outside of the breast area.
Lymph nodes - Structures in the lymphatic system that act as filters, catching bacteria and cancer cells, and contribute to the body's immune system, which fights infection and disease.
Lymphatic Vessels - Vessels that remove cellular waste and infection from the body by filtering through lymph nodes and eventually emptying into the vascular (blood) system.
Lymphedema - A swelling in hand and arm caused by excess fluid that collects after the lymph nodes have been removed by surgery or affected by radiation treatments.
Lymphocytes - Cells that travel in the bloodstream to and from the lymph nodes, providing the body with immune capability.