Macrocyst - A cyst that is large and can usually be felt with the fingers.
Macroscopic - Visible to the naked eye; gross observation.
Magnification View - Special enlarged views used in mammography to magnify an area for a more detailed examination of a suspicious finding.
Main tumor - A spontaneous new growth of tissue made up of abnormally dividing cells that form a mass.
Malignant - Cancerous.
Malignant Tumor - A mass of cancer cells. These cells have uncontrolled growth and will invade surrounding tissues and spread to distant sites of the body, setting up new cancer sites.
Mammaplasty - Breast operation to alter breast size.
Mammary Duct Ectasia - A non-cancerous breast disease most often found in women during menopause. The ducts in or beneath the nipple become clogged with cellular and fatty debris. The duct may have gray to greenish discharge, a lump that can be felt and can become inflamed, causing pain.
Mammary Glands - The breast glands that produce and carry milk by way of the mammary ducts to the nipples during pregnancy and breast feeding.
Mammary Ridge - A ridge of firm tissue located at the base of the breasts along the underwire area of a bra.
Mammogram - An x-ray of the breast detailing the structure of breast tissue; requires only low doses of radiation.. A baseline mammogram is performed on healthy breasts usually at the age of 35 to establish a basis for later comparison.
Mammography - Process of taking breast x-ray films to detect breast cancer.
Mammoplasty - Plastic surgery of the breasts to decrease or increase size and alter shape.
Mammotest - Biopsy performed under mammography while breast is compressed and lesion is viewed by physician. Sample of lesion is removed using a large core needle and is then sent to lab to determine flit is benign or malignant. Also known as stereotactic biopsy.
Margins - The area of tissue surrounding a tumor when it is removed by surgery.
Markers - Blood tests that register tumor antigens.
Mastalgia - Pain in the breast.
Mastectomy - Surgical removal of the breast, usually for treatment of cancer.
Mastiffs - Infection occurring in the breast. Pain, tenderness, swelling, redness and warmth may be observed. Usually related to infection and will respond to antibiotic treatment.
Mastitis - Inflammation of the breast, usually caused by bacterial infection during breast-feeding, the organisms responsible gaining access through cracked nipples. Cystic mastitis does not involve inflammation, but the presence of cysts (thought to be caused by hormonal factors) causes the breast(s) to be lumpy.
Mastodynia - Pain in the breast.
Mastopexy - Breast lift to tighten the breast by removing sagging skin caused by the forces of gravity and the effects of aging.
Mediport - A temporary device that is surgically implanted in the chest or arm to accept an IV during chemotherapy.
Meiosis - The process during cell division when the diploid chromosome number becomes reduced to the haploid.
Menopause - The cessation of menstruation result of aging and the ovaries produce lower levels of sex hormones; usually occurs between the age of 45 and 55.
Menstrual cycle and menstruation - The cyclical nature of the reproductive life of a sexually mature female. One ovum develops and matures within a Graafian follicle in one of the ovaries. When mature, the follicle ruptures to release the egg, which passes down the Fallopian tube to the uterus. The ruptured follicle becomes a temporary endocrine gland, called the corpus luteum which secretes the hormone progesterone. Under the influence of progesterone, the uterus wall (endometrium) thickens and its blood supply increases in readiness for the implantation of a fertilized egg. If the egg is not fertilized and there is no pregnancy, the thickened endometrium is shed along with a flow of blood through the vagina (menstruation). The usual age at which menstruation starts is 12 to 15 but it can be as early as 10 or as late as 20. The duration varies and can be anything from 2 to 8 days, the whole cycle usually occupying about 29 to 30 days.
Metastasis - Spread of cancer from one part of the body to another. It can spread through the lymphatic system, the bloodstream, or across body cavities.
Metastatic disease - Movement of cancer cells from one part of the body to another.
Microcalcificafion - Tiny calcifications in the breast tissue usually seen only on a mammogram. The presence of clusters may be a sign of ductal carcinoma in situ.
Microcyst - A cyst that is too small to be felt but may be observed on a mammogram or ultrasound screening.
Microinvasion - Invasion of cancer cells through the breast duct into adjacent tissue at a microscopic level.
Micrometastasis - Undetectable spread of cancer outside the breast that is not seen on routine screening tests. Metastasis is too limited to have created enough mass to be observed.
Microscopic focus - The starting point of a disease process,
Microsurgical breast reconstruction - Method of breast reconstruction whereby a flap of a woman's own tissue is moved from a distant area of the body such as the abdomen, back, thigh, or buttocks to the chest wall area to build a breast. Once this tissue is transferred, the blood vessels are sutured and reattached under the magnification of the operating microscope.
Mitochondria - The source of energy for a cell; involved with protein synthesis and lipid metabolism.
Mitosis - The reproduction of cells; the process of cell division.
Mitotic rate - Rate or speed of cell division.
Modified radical mastectomy - Surgical removal of the breast, some fat, and most of the lymph nodes in the armpit, leaving the chest wall muscles largely intact.
Morning sickness - Vomiting and nausea, most common during the first three months of pregnancy.
Mulficentric - More than one origin. Cancer cells may grow in several locations within the breasts and not be related to each other.
Muscle flap - A muscle or portion of muscle that can be transferred with its blood supply to another part of the body for reconstructive purposes.
Musculocutaneous (myocutaneous) - Muscle and skin.
Musculoskeletal Pain - Breast pain which is caused by a pinched nerve in the back, a back injury, scoliosis, arthritis or osteoporosis.
Mutation - Any basic alteration in form, quality, or some other characteristic. A change in genetic material of a chromosome that produces a new individual atom like its parents.