Dictionary

mastocytoma A benign nodular tumor on the skin, rich in mast cells, that is usually present at birth or in early childhood and resolves spontaneously. Also called a mast cell tumor. See also mast cell.

mastocytosis A condition characterized by infiltration of mast cells into the tissues of the body. Mast cells are connective tissue cells which release chemicals, including histamine, that cause itching, swelling, and fluid leakage from cells. There are several different clinical forms of mastocytosis. See also mast cell; mastocytoma.

mastoid The rounded protrusion of bone just behind the ear. The mastoid was once thought to look like a breast (hence its name).

mastoiditis Inflammation of the mastoid, which often occurs secondarily to ear infection.

maternal mortality rate The number of registered maternal deaths due to birth- or pregnancyrelated complications per 100,000 registered live births.

maternal serum alpha-fetoprotein The presence of alpha-fetoprotein (AFP), a plasma protein that is normally produced by the fetus, in the mother’s blood. Abbreviated MSAFP. MSAFP serves as the basis for some valuable tests. AFP is manufactured principally in the fetus’s liver but is also found in the fetal gastrointestinal tract and in the yolk sac,…

maxilla The major bone of the upper jaw.

MCAT Medical College Admissions Test.

McBurney point The most tender area of the abdomen of patients in the early stage of appendicitis.

McCune-Albright syndrome See polyostotic fibrous dysplasia.

MD Abbreviation for the Latin Medicinae Doctor, “doctor of medicine.”

measles An acute and highly contagious viral disease characterized by fever, runny nose, cough, red eyes, and a spreading skin rash. Measles can be complicated by ear infections, pneumonia, encephalitis (which can cause convulsions, mental retardation, and even death), the sudden onset of low blood platelet levels with severe bleeding (acute thrombocytopenic purpura), or a…