Disease & Drug Information

Glossary of Terms


A monoclonal antibody that is being studied in the treatment of some types of cancer. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. M200 binds to a protein that is found on cells that line some tumor blood vessels. It is a type of angiogenesis inhibitor. Also called volociximab.

ma huang

listen (mah hwong) A shrub native to China and India. The stems and roots are used in traditional medicine as a diuretic and for asthma, bronchitis, and cough. It has also been promoted as a decongestant, a weight loss aid, and as a supplement to increase energy. Ma huang may cause high blood pressure, increased heart rate, or death if used with certain drugs, and may reduce the effects of certain drugs used to treat cancer and other diseases. The U.S. Food and Drug Administration has banned the sale of dietary supplements that contain ma huang. The scientific name is Ephedra sinica. Also called ephedra.


listen (MA-kroh-KAL-sih-fih-KAY-shun) A small deposit of calcium in the breast that cannot be felt but can be seen on a mammogram. It is usually caused by aging, an old injury, or inflamed tissue and is usually not related to cancer.


listen (MA-kroh-GLAH-byoo-lih-NEE-mee-uh) A condition in which the blood contains high levels of large proteins and is too thick to flow through small blood vessels. One type is Waldenstrm macroglobulinemia, which is a type of cancer.


listen (MA-kroh-fayj) A type of white blood cell that surrounds and kills microorganisms, removes dead cells, and stimulates the action of other immune system cells.

macular degeneration

listen (MA-kyoo-ler dee-JEH-neh-RAY-shun) A condition in which there is a slow breakdown of cells in the center of the retina (the light-sensitive layers of nerve tissue at the back of the eye). This blocks vision in the center of the eye and can cause problems with activities such as reading and driving. Macular degeneration is most often seen in people who are over the age of 50. Also called age-related macular degeneration, AMD, and ARMD.


listen (muh-FOS-fuh-mide) A form of cyclophosphamide that can be administered as an intrathecal infusion. Mafosfamide is being studied as an anticancer drug. It belongs to the family of drugs called alkylating agents.

MAGE-3 antigen

listen (... AN-tih-jen) A protein found in many types of tumors but not in most normal tissues. Vaccines using pieces of the MAGE-3 protein are being studied for their ability to boost the immune response to cancer cells in patients with cancer.


listen (mag-NEE-zee-um) In medicine, a mineral used by the body to help maintain muscles, nerves, and bones. It is also used in energy metabolism and protein synthesis.

magnesium sulfate

listen (mag-NEE-zee-um SUL-fayt) A drug used to treat pre-eclampsia and eclampsia (serious complications of pregnancy). Magnesium sulfate is also being studied for its ability to prevent the toxic side effects of certain drugs used to treat colorectal cancer. It is a type of anticonvulsant agent.

magnetic resonance angiography

listen (mag-NEH-tik REH-zuh-nunts an-jee-AH-gruh-fee) A procedure that uses radio waves and a powerful magnet linked to a computer to create detailed pictures of the blood vessels and blood flow inside the body. A dye may be injected into a vein to make the blood vessels and blood flow easier to see. Magnetic resonance angiography may be used to check for aneurysms (a bulge in the blood vessel wall), blockages in the arteries, blood clots, and other blood vessel problems. Also called MRA.

magnetic resonance imaging

listen (mag-NEH-tik REH-zuh-nunts IH-muh-jing) A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body. These pictures can show the difference between normal and diseased tissue. Magnetic resonance imaging makes better images of organs and soft tissue than other scanning techniques, such as computed tomography (CT) or x-ray. Magnetic resonance imaging is especially useful for imaging the brain, the spine, the soft tissue of joints, and the inside of bones. Also called MRI, NMRI, and nuclear magnetic resonance imaging.

magnetic resonance perfusion imaging

listen (mag-NEH-tik REH-zuh-nunts per-FYOO-zhun IH-muh-jing) A special type of magnetic resonance imaging (MRI) that uses an injected dye in order to see blood flow through tissues. Also called perfusion magnetic resonance imaging.

magnetic resonance spectroscopic imaging

listen (mag-NEH-tik REH-zuh-nunts SPEK-troh-SKAH-pik IH-muh-jing) A noninvasive imaging method that provides information about cellular activity (metabolic information). It is used along with magnetic resonance imaging (MRI) which provides information about the shape and size of the tumor (spatial information). Also called 1H-nuclear magnetic resonance spectroscopic imaging, MRSI, and proton magnetic resonance spectroscopic imaging.

magnetic-targeted carrier

listen (mag-NEH-tik-TAR-geh-ted KAYR-ee-er) A tiny bead made from particles of iron and carbon that can be attached to an anticancer drug. A magnet applied from outside the body then can direct the drug to the tumor site. This can keep a larger dose of the drug at the tumor site for a longer period of time, and help protect healthy tissue from the side effects of chemotherapy.


listen (MAG-neh-vist) A substance used in magnetic resonance imaging (MRI) to help make clear pictures of the brain, spine, heart, soft tissue of joints, and inside bones. Magnevist is being studied in the diagnosis of cancer. It is a type of contrast agent. Also called gadopentetate dimeglumine and Gd-DTPA.

maidenhair tree

listen (MAY-din-HAYR...) A tree native to China. Substances taken from the leaves and seeds have been used in some cultures to treat certain medical problems. Maidenhair tree has been studied in the prevention and treatment of Alzheimer disease, dementia, certain blood vessel diseases, and memory loss. It may cause bleeding or high blood pressure when used with certain drugs. Also called ginkgo and ginkgo biloba.

mainstream medicine

listen (MAYN-streem MEH-dih-sin) A system in which medical doctors and other healthcare professionals (such as nurses, pharmacists, and therapists) treat symptoms and diseases using drugs, radiation, or surgery. Also called allopathic medicine, biomedicine, conventional medicine, orthodox medicine, and Western medicine.

mainstream smoke

listen (MAYN-streem ...) Tobacco smoke that is exhaled by smokers. Mainstream smoke can be a form of secondhand smoke. It contains nicotine and many harmful, cancer-causing chemicals. Inhaling mainstream smoke increases the risk of lung cancer and may increase the risk of other types of cancer. Inhaling it also increases the risk of other health problems, such as heart disease and lung disease.

maintenance therapy

listen (MAYN-teh-nunts THAYR-uh-pee) Treatment that is given to help keep cancer from coming back after it has disappeared following the initial therapy. It may include treatment with drugs, vaccines, or antibodies that kill cancer cells, and it may be given for a long time.

malabsorption syndrome

listen (MA-lub-SORP-shun SIN-drome) A group of symptoms such as gas, bloating, abdominal pain, and diarrhea resulting from the body's inability to properly absorb nutrients.

male breast cancer

listen (mayl brest KAN-ser) Cancer that forms in tissues of the breast in men. Most male breast cancer begins in cells lining the ducts. It is very rare and usually affects older men.


listen (muh-LIG-nun-see) A term for diseases in which abnormal cells divide without control and can invade nearby tissues. Malignant cells can also spread to other parts of the body through the blood and lymph systems. There are several main types of malignancy. Carcinoma is a malignancy that begins in the skin or in tissues that line or cover internal organs. Sarcoma is a malignancy that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is a malignancy that starts in blood-forming tissue, such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are malignancies that begin in the cells of the immune system. Central nervous system cancers are malignancies that begin in the tissues of the brain and spinal cord. Also called cancer.


listen (muh-LIG-nunt) Cancerous. Malignant cells can invade and destroy nearby tissue and spread to other parts of the body.

malignant ascites

listen (muh-LIG-nunt uh-SY-teez) A condition in which fluid containing cancer cells collects in the abdomen.

malignant ectomesenchymoma

listen (muh-LIG-nunt EK-toh-MEH-zen-ky-MOH-muh) A rare, fast-growing tumor of the nervous system or soft tissue that occurs in children and young adults. Malignant ectomesenchymomas may form in the head and neck, abdomen, perineum, scrotum, or limbs. Also called ectomesenchymoma.

malignant fibrous cytoma

listen (muh-LIG-nunt FY-brus sy-TOH-muh) A soft tissue sarcoma that usually occurs in the limbs, most commonly the legs, and may also occur in the abdomen. Also called malignant fibrous histiocytoma.

malignant fibrous histiocytoma

listen (muh-LIG-nunt FY-brus HIS-tee-oh-sy-TOH-muh) A soft tissue sarcoma that usually occurs in the limbs, most commonly the legs, and may also occur in the abdomen. Also called malignant fibrous cytoma.

malignant meningioma

listen (muh-LIG-nunt meh-NIN-jee-OH-muh) A rare, fast-growing tumor that forms in one of the inner layers of the meninges (thin layers of tissue that cover and protect the brain and spinal cord). Malignant meningioma often spreads to other areas of the body.

malignant mesothelioma

listen (muh-LIG-nunt MEH-zoh-THEE-lee-OH-muh) A rare type of cancer in which malignant cells are found in the lining of the chest or abdomen. Exposure to airborne asbestos particles increases one's risk of developing malignant mesothelioma.

malignant mixed Müllerian tumor

listen (muh-LIG-nunt mikst myoo-LAYR-ee-un TOO-mer) A rare type of tumor that is a mixture of carcinoma and sarcoma cells. MMMT usually occurs in the uterus. Also called MMMT.

malignant pericardial effusion

listen (muh-LIG-nunt PAYR-ih-KAR-dee-ul eh-FYOO-zhun) A condition in which cancer causes extra fluid to collect inside the sac around the heart. The extra fluid causes pressure on the heart, which keeps it from pumping blood normally. Lymph vessels may be blocked, which can cause infection. Malignant pericardial effusions are most often caused by lung cancer, breast cancer, melanoma, lymphoma, and leukemia.

malignant peripheral nerve sheath tumor

listen (muh-LIG-nunt peh-RIH-feh-rul ... TOO-mer) A type of soft tissue sarcoma that develops in cells that form a protective sheath (covering) around peripheral nerves, which are nerves that are outside of the central nervous system (brain and spinal cord). Also called MPNST.

malignant peritoneal effusion

listen (muh-LIG-nunt PAYR-ih-toh-NEE-ul eh-FYOO-zhun) A condition in which cancer causes extra fluid to collect between the thin layers of the peritoneum (tissue that lines the abdomen and covers most of the organs in the abdomen). Signs and symptoms may include pain or swelling in the abdomen, trouble breathing, chest pain, weight gain, nausea, loss of appetite, and fatigue. Malignant peritoneal effusions are most often caused by cancers of the ovary, uterus, breast, colon, lung, pancreas, and liver.

malignant pleural effusion

listen (muh-LIG-nunt PLOOR-ul eh-FYOO-zhun) A condition in which cancer causes an abnormal amount of fluid to collect between the thin layers of tissue (pleura) lining the outside of the lung and the wall of the chest cavity. Lung cancer, breast cancer, lymphoma, and leukemia cause most malignant pleural effusions.


listen (mal-NER-isht) Describes a condition caused by not getting enough calories or the right amount of key nutrients needed for health. Key nutrients include vitamins and minerals.


listen (mal-noo-TRIH-shun) A condition caused by not getting enough calories or the right amount of key nutrients, such as vitamins and minerals, that are needed for health. Malnutrition may occur when there is a lack of nutrients in the diet or when the body cannot absorb nutrients from food. Cancer and cancer treatment may cause malnutrition.


listen (MA-lon-dy-AL-deh-hide) A byproduct of lipid (fat) metabolism in the body. It is also found in many foods and can be present in high amounts in rancid food.

MALT lymphoma

listen (... lim-FOH-muh) A type of cancer that arises in cells in mucosal tissue that are involved in antibody production. Also called mucosa-associated lymphoid tissue lymphoma.

mammalian target of rapamycin

listen (muh-MA-lee-un TAR-get RA-puh-MY-sin) A protein that helps control several cell functions, including cell division and survival, and binds to rapamycin and other drugs. Mammalian target of rapamycin may be more active in some types of cancer cells than it is in normal cells. Blocking mammalian target of rapamycin may cause the cancer cells to die. It is a type of serine/threonine protein kinase. Also called mechanistic target of rapamycin and mTOR.