+ -Text Size

 

Cancer Glossary

Search for your term

Browse the glossary by selecting a letter or by entering a cancer-related term:

M
 Search  [MACK-row-GLOB-yuh-lin-EE-mee-uh]
A condition in which there are too many large proteins in the blood, which may reduce or clog blood flow in the smaller blood vessels. Waldenstrom macroglobulinemia is a type of non-Hodgkin lymphoma with such proteins. See also non-Hodgkin lymphoma, Waldenstrom macroglobulinemia.
 Search  [MACK-ro-faj]
A type of white blood cell that engulfs and destroys foreign materials. See also white blood cells.
 Search 
Often shortened to MRI. A method of taking detailed pictures of the inside of the body. Instead of using x-rays, MRI uses a powerful magnet to send radio waves through the body. The images appear on a computer screen as well as on film. Like x-rays, the procedure is painless, but some people may feel confined inside the MRI machine. See also imaging tests, x-ray.
 Search  [muh-LIG-nunt]
Cancerous; dangerous or likely to cause death if untreated. Compare with benign. See also cancer.
 Search  [MEZ-oh-THEE-lee-OH-muh]
A rare cancer that starts in the covering of the lungs (pleura), the heart (pericardium), or the lining of the abdomen (peritoneum). An extremely rare form can affect the inner covering of the testicles.
 Search  [muh-LIG-nunt TOO-mer or TYOO-mer]
A mass of cancer cells that may invade nearby tissues or spread (metastasize) to distant areas of the body. Not all cancers form tumors, and not all tumors are malignant. See also malignant, tumor.
 Search  [MAM-uh-ree]
Having to do with the breast.
 Search 
Lymph nodes that are inside the chest near the breastbone (sternum). See also lymph nodes.
 Search  [MAM-uh-GRAM]
Also called mammography (mam-Ah-gruff-ee). An x-ray of the breast; a method of finding breast cancer that can’t be felt using the fingers. Mammograms are done with a special type of x-ray machine used only for this purpose. Screening mammograms are used to help find breast cancer early in women who don’t have any symptoms. Diagnostic mammograms help the doctor learn more about breast lumps or the cause of breast changes. See also screening, x-ray.
 Search 
Any plastic surgery to rebuild the breast or to change the shape, size, or position of the breast. Reduction mammoplasty reduces the size of the breast. Augmentation mammoplasty enlarges a woman’s breast, usually with implants. See also breast reconstruction, implants.
 Search  [MAR-jin]
In cancer surgery or biopsy, the tissue beyond the visible edge of the tumor or abnormal tissue that’s removed along with the tumor or area of concern in an effort to get all of the cancer. See also surgical margin.
 Search 
Any sort of lump, which may or may not be cancer. See also tumor.
 Search  [mas-TEK-tuh-me]
urgery to remove all or part of the breast and sometimes other tissue. Some of the more common types of mastectomies are listed below.

  • Modified radical mastectomy removes the breast, skin, nipple, areola, and most of the axillary lymph nodes on the same side, leaving the chest muscles intact.


  • Partial or segmental mastectomy removes only the part of the breast that has the cancer and a margin of healthy breast tissue around the tumor. Also called breast-conserving surgery or lumpectomy.


  • Prophylactic mastectomy is a mastectomy done before any evidence of cancer can be found, for the purpose of preventing cancer.


  • Quadrantectomy (QUAD-runt-EK-tuh-me) is a partial mastectomy in which the quarter of the breast that has a tumor is removed.


  • Radical mastectomy removes the breast, skin, nipple, areola, both chest (pectoral) muscles, and all axillary lymph nodes on the same side.


  • Simple mastectomy or total mastectomy removes only the breast, skin, nipple, and areola.


  • Skin-sparing mastectomy leaves as much of the breast skin as possible (but removes the nipple and areola) to improve the way the reconstructed breast looks.


  • See also areola, axillary dissection, lymph node, nipple, surgical margin.
     Search  [mass-TIE-tiss]
    Inflammation or infection of the breast.
     Search  [ME-dee-uh-STY-nul]
    Related to a part of the body that lies between other parts. In cancer care, often refers to the area in the center of the chest, between the lungs. See also mediastinum.
     Search  [ME-dee-uh-stine-AH-skuh-pee]
    Examination of the space between the lungs using a thin, lighted, flexible tube inserted under the chest bone (sternum). This lets the doctor see the lymph nodes in this area and remove samples to check for cancer. See also biopsy, lymph node.
     Search  [ME-dee-uh-STY-num]
    Any structure or area of the body that’s between other parts. Commonly refers to the central part of the chest, which is surrounded by the breastbone (sternum), the backbone, and both lungs. The chest mediastinum contains the heart, large blood vessels, main breathing tube (trachea), swallowing tube (esophagus), and lymph nodes. See also lymph nodes.
     Search  [MED-ih-kull on-KAHL-uh-jist]
    A doctor who is specially trained to diagnose and treat cancer with chemotherapy and other drugs. See also cancer care team, chemotherapy.
     Search 
    See durable power of attorney for health care.
     Search  [MED-you-LAIR-ee]
    A special type of invasive ductal carcinoma of the breast. There’s also a rare medullary type of thyroid cancer. See also invasive ductal carcinoma.
     Search  [mel-AN-o-sites]
    The cells that make the brown pigment called melanin that gives skin its color.
     Search  [MEL-uh-NO-muh]
    A cancerous tumor that starts in the cells called melanocytes that make the skin coloring. When found in the skin or under the nails, it’s called cutaneous melanoma, but it can grow in many other parts of the body, including the eyes, mouth, and genitals. It’s almost always curable when found early, but it can spread quickly if not treated.
     Search  [MEN-ar-key or men-AR-key]
    A woman’s first menstrual period. Early menarche (before age 12) is a risk factor for breast cancer, possibly because the earlier a woman’s periods begin, the longer the breasts are exposed to estrogen. See also estrogen, risk factor.
     Search  [muh-NIN-jeez]
    The 3 thin layers of tissue the cover the brain and spinal cord. See also brain, intrathecal, spinal cord.
     Search 
    The use of estrogen (and often progesterone) from an outside source after the body has stopped making its own supply because of natural or induced menopause. This type of hormone therapy is sometimes given to relieve symptoms of menopause. Studies have found that taking estrogen and progesterone together increases breast cancer risk, as well as the risk of heart disease and blood clots, although it might lower the risk of colorectal cancer. See also estrogen, estrogen therapy, menopause, progesterone.
     Search  [MEN-uh-paws]
    The phase in a woman’s life when monthly cycles of menstruation stop. During this time, hormone levels typically fluctuate before they stabilize at much lower levels. Menopause usually takes place in a woman’s late 40s or early 50s, but it can also be brought on suddenly by surgical removal of both ovaries (oophorectomy), or by some chemotherapies that destroy ovarian function. See also chemotherapy, estrogen, hormone, ovary.
     Search 
    The molecule that carries the information from the DNA (deoxyribonucleic acid) genetic code to the parts of the cell that make proteins. See also deoxyribonucleic acid, ribonucleic acid.
     Search  [muh-TACK-ruh-nus]
    Happening at different times. Compare to synchronous.
     Search  [meh-TAS-tuh-sis]
    The spread of cancer cells to one or more sites elsewhere in the body, often by way of the lymph system or bloodstream. Distant metastasis is spread to organs or tissues that are farther away (such as when lung cancer spreads to the brain). The plural of this word is metastases (meh-TAS-tuh-sees). See also cancer, lymph node, lymph system, primary site.
     Search  [meh-TAS-tuh-SIZE]
    To spread to one or more sites elsewhere in the body, often by way of the lymph system or bloodstream. See also lymph system, metastasis.
     Search  [MEH-tuh-STAT-ick]
    Used to describe cancer that has spread from where it started (the primary site) to other structures or organs. See also metastasis.
     Search 
    Also written as m. A metric measure of length. It takes about 39.37 inches (or 100 centimeters) to equal 1 meter. See also centimeter, millimeter.
     Search 
    See calcifications.
     Search  [MIKE-row-muh-TAS-tuh-sis]
    The spread of cancer cells in groups so small that they can only be seen under a microscope.
     Search  [MY-crow-SAT-uh-lite IN-stuh-BILL-uh-tee]
    Also called MSI. A type of genetic mutation often linked to hereditary non-polyposis colon cancer (HNPCC). This mutation causes size differences in sections of DNA (deoxyribonucleic acid) that are normally the same size in all cells. Testing for MSI is done on tissue taken from the cancer to find out if the DNA is of different lengths; if it is, HNPCC genetic testing is usually offered. See also deoxyribonucleic acid, genetic testing, hereditary non-polyposis colon cancer, mutation.
     Search 
    An operation that uses a microscope to see and attach very tiny blood vessels to each other.
     Search 
    A way of treating cancer in a few sites, such as the liver, by using heat to destroy the cells. See also ablation.
     Search 
    Also written as mm. A metric measure of length that is 1/1000 of a meter. 10 mm = 1 centimeter, and 1,000 mm = a meter. About 25 mm (or 2.5 cm) = 1 inch. See also centimeter, meter.
     Search 
    Unit of radiation exposure. See also radiation dose.
     Search 
    Unit of radiation exposure. See also radiation dose.
     Search 
    A type of allogeneic stem cell transplant in which lower doses of conditioning treatment are used before the transplant. This allows some of the patient’s own bone marrow stem cells to survive, which lowers the risk of very low blood counts during engraftment. The new stem cells kill off the patient’s stem cells over time, after the transplant engrafts or “takes.” See also allogeneic stem cell transplant, blood count, bone marrow, hematopoietic stem cell transplant, reduced-intensity conditioning, stem cells.
     Search 
    See mastectomy.
     Search  [MA-nuh-KLO-nuhl]
    Man-made antibodies that are designed to lock onto certain antigens (substances that can be recognized by the immune system). Monoclonal antibodies have several uses in diagnosing and treating cancer. They are often used to help detect and classify cancer cells under a microscope. “Naked” monoclonal antibodies can attach to parts of cancer cells to either affect the cells directly or mark the cells so they can be found and attacked by the immune system. Other monoclonal antibodies are attached to chemotherapy drugs or radioactive substances and deliver these treatments directly to the cancer cells, killing them with little risk of harming healthy tissue. Research is still going on to learn more ways they can be used to find and treat cancer. See also antibody, antigen, chemotherapy, imaging tests, immunocytochemistry.
     Search  [mor-BID-ih-tee]
    Rate of a disease or condition in a population or group; the number of people who have a disease or condition. See also incidence, prevalence.
     Search  [mor-FOL-uh-jee]
    In cancer, how cells look under the microscope, including shape, structure, pattern, color, and other aspects of their appearance..
     Search  [mor-TAL-uh-tee]
    Death or being subject to death. Mortality rate is a measure of the rate of death from a disease, also called death rate.
     Search 
    See magnetic resonance imaging.
     Search  [MEW-sin-us CAR-sin-O-ma]
    A type of carcinoma that is formed by mucus-producing cancer cells. See also carcinoma.
     Search  [mew-KO-suh]
    See mucous membrane.
     Search  [mew-ko-SITE-us]
    Inflammation of a mucous membrane, such as the lining of the mouth. See also mucous membrane.
     Search 
    Also called mucosa. The moist inner lining layer of the mouth, throat, eyelids, nose, urethra, vagina, and digestive system. See also digestive system, urethra, vagina.
     Search  [MEW-kus]
    The thick fluid secreted by mucous membranes and mucous glands. See also mucous membrane.
     Search 
    Often shortened to MDR. Resistance of cancer cells to several types of chemotherapy drugs, typically after being exposed to chemotherapy. May also refer to infections that can no longer be cured by the usual antibiotics. See also chemotherapy.
     Search 
    a type of cancer that starts in the plasma cells. Normal plasma cells are mainly found in the bone marrow and are an important part of the body’s immune system. When plasma cells grow out of control, they can form tumors, usually in the bone marrow. If only one tumor forms, it is called solitary (or isolated) plasmacytoma. See also bone marrow, immune system.
     Search  [MUS-kyu-LAIR-is myoo-KO-say or myoo-KO-sa]
    The thin inner muscle layer of the digestive tract that is between the mucosa and the submucosa. See also digestive system, colon.
     Search  [MUS-kyu-LAIR-is PRO-pree-uh]
    The thick muscle layer that’s part of the wall in most parts of the digestive tract. This is the furthest muscle layer from the center of the tube. See also digestive system, colon.
     Search  [mew-TAY-shun]
    A change in the DNA (deoxyribonucleic acid) of a cell. Most mutations do not cause cancer, and a few may even be helpful. But all types of cancer are thought to be due to mutations that damage a cell’s DNA. Some cancer-related mutations can be passed on from a parent (inherited). This means that the person is born with the mutated DNA in all the body’s cells. But most mutations happen after a person is born. These are called somatic or acquired mutations. This type of mutation happens in one cell at a time, and only affects cells that arise from the single mutated cell. See also cancer susceptibility genes, deoxyribonucleic acid, gene, inherited mutation, somatic mutation.
     Search  [MY-uh-lo-uh-BLAY-tiv]
    Treatment that destroys the bone marrow. It’s often used before a stem cell transplant. See also bone marrow, hematopoietic stem cell transplant, conditioning treatment.
     Search  [MY-uh-lo-dis-PLAS-tik]
    Often shortened to MDS. A type of cancer in which damaged cells in the bone marrow make defective blood cells. The body destroys the defective cells, which can leave a person with low blood counts. In some cases MDS can progress to leukemia. See also bone marrow, complete blood count, leukemia.
     Search  [MY-uh-loid loo-KEY-me-uh]
    Also called myelocytic (MY-uh-lo-SIH-tik) leukemia, myelogenous (MY-uh-LAH-jen-us) leukemia, and/or non-lymphocytic (non-LIM-fo-SIH-tik) leukemia. A type of cancer that starts in cells in the bone marrow that are supposed to mature into different types of blood cells. Myeloid leukemia can be chronic (CML) or acute (AML). There are a number of subtypes of acute myeloid leukemia (AML), some with genetic abnormalities that can affect the success of treatment. Compare to lymphoid leukemia. See also bone marrow, leukemia.