Glossary of Medical Terms

A substance being studied in the prevention of breast cancer in women at high risk of breast cancer. Acolbifene hydrochloride binds to estrogen receptors in the body and blocks the effects of estrogen in the breast. It is a type of selective estrogen receptor modulator (SERM).

Having to do with sound or hearing.

A genetic condition in which tumors form on the nerves of the inner ear and cause loss of hearing and balance. Tumors may also occur in the brain and on nerves in the skull and spinal cord, and may cause loss of speech, eye movement, and the ability to swallow. Also called neurofibromatosis type 2 and NF2.

A type of immunity that develops when a person’s immune system responds to a foreign substance or microorganism, or that occurs after a person receives antibodies from another source. The two types of acquired immunity are adaptive and passive. Adaptive immunity occurs in response to being infected with or vaccinated against a microorganism. The body makes an immune response, which can prevent future infection with the microorganism. Passive immunity occurs when a person receives antibodies to a disease or toxin rather than making them through his or her own immune system.

A disease caused by the human immunodeficiency virus (HIV). People with acquired immunodeficiency syndrome are at an increased risk for developing certain cancers and for infections that usually occur only in individuals with a weak immune system. Also called AIDS.

A rare disorder in which the bone marrow makes almost no red blood cells. It may be caused by infection or by certain drugs. Patients with this disorder may also have a thymoma (a tumor of the thymus) or an autoimmune condition such as lupus erythematosus or rheumatoid arthritis.

A rare condition in which blood clots form in small blood vessels throughout the body. These clots can block the flow of blood and oxygen to the body’s organs, which leads to a lower-than-normal number of platelets in the blood. Signs and symptoms of acquired thrombotic thrombocytopenic purpura include purple bruises or tiny red or purple spots on the skin, bleeding problems, anemia, fever, chest pain, nervous system problems, and kidney problems. acquired thrombotic thrombocytopenic purpura occurs when the body starts producing antibodies that block an enzyme called ADAMTS13, which is involved in blood clotting. It may be brought on by certain diseases or conditions (such as pregnancy, cancer, lupus, HIV, or other infections), certain medicines (such as chemotherapy or hormone therapy), or certain procedures (such as surgery or a stem cell transplant). acquired thrombotic thrombocytopenic purpura usually occurs in adults. Also called aTTP.

A substance being studied in the treatment of cancer. It is a type of topoisomerase inhibitor. Also called DACA.

A condition in which the pituitary gland makes too much growth hormone after normal growth of the skeleton is finished. This causes the bones of the hands, feet, head, and face to grow larger than normal. Acromegaly can be caused by a pituitary gland tumor.

A substance used to make plastics, rubber, and textiles. Being exposed to acrylonitrile may increase the risk of developing certain cancers, such as lung, brain, or prostate cancer.