Glossary of Medical Terms

In medicine, describes a tumor or disease that forms, grows, or spreads quickly. It may also describe treatment that is more severe or intense than usual.

A type of soft tissue tumor that forms in fibrous (connective) tissue, usually in the arms, legs, or abdomen. It may also occur in the head and neck. Aggressive fibromatoses are usually benign (not cancer). They often recur (come back) after treatment and spread to nearby tissue, but they rarely spread to other parts of the body. They may occur in adults or children. Also called desmoid tumor and desmoid-type fibromatosis.

A type of lymphoma that grows and spreads quickly and has severe symptoms. Also called high-grade lymphoma and intermediate-grade lymphoma.

A rare condition in which too many mast cells (a type of white blood cell) build up in certain tissues and organs in the body, including the bone marrow, lymph nodes, bone, liver, spleen, and small intestine. Aggressive systemic mastocytosis may get worse quickly and cause severe symptoms and organ damage. Sometimes, it may become mast cell leukemia (a very rare type of leukemia). Aggressive systemic mastocytosis usually occurs in adults. Also called ASM.

A condition in which a person is unable to relax and be still. The person may be very tense and irritable, and become easily annoyed by small things. He or she may be eager to have an argument, and be unwilling to work with caregivers to make the situation better.

A progressive, chronic disease in which the bone marrow is replaced by fibrous tissue and blood is made in organs such as the liver and the spleen, instead of in the bone marrow. This disease is marked by an enlarged spleen and progressive anemia. Also called chronic idiopathic myelofibrosis, idiopathic myelofibrosis, myelosclerosis with myeloid metaplasia, and primary myelofibrosis.

A drug or substance that binds to a receptor inside a cell or on its surface and causes the same action as the substance that normally binds to the receptor.

An intense fear of being in open places or in situations where it may be hard to escape, or where help may not be available. People with agoraphobia are usually very anxious about having a panic attack in a public place. They may also have a fear of being alone or have trouble leaving their home. They usually avoid elevators, bridges, and public places. Agoraphobia is a type of phobia and a type of anxiety disorder.

A type of white blood cell. Monocytes and lymphocytes are agranulocytes.

A serious condition that occurs when there is an extremely low number of granulocytes (a type of white blood cell) in the blood. Granulocytes are an important part of the immune system and help the body fight infection. Having very low levels of granulocytes in the blood can lead to serious or life-threatening infections. Signs and symptoms of agranulocytosis include fever, chills, weakness, sore throat, sores in the mouth or throat, bleeding gums, bone pain, low blood pressure, fast heartbeat, and trouble breathing. Agranulocytosis may be inherited or caused by certain autoimmune or bone marrow disorders, infection, poor nutrition, cancer treatment (such as chemotherapy or bone marrow transplant), or exposure to certain toxins, chemicals, or medicines.