acute lymphocytic leukemia (ALL): a type of leukemia, or cancer of the blood and blood forming tissue, where many abnormal lymphocytes (a type of white blood cell) are produced by the body.

acute myelogenous leukemia (AML): a type of leukemia, or cancer of the blood and blood forming tissue, where many abnormal granulocytes (a type of white blood cell) are produced by the body.

allogeneic transplantation: a procedure where cells, tissue, or organs are transplanted to a person from a compatible donor.

alopecia: a skin disease in which there is hair loss on the scalp and sometimes elsewhere on the body.

alternative therapy: any healing practices that are not part of mainstream medicine that means any practice that is not widely taught in medical schools or frequently used by doctors or in hospitals. Alternative medicine is often used instead of conventional medical techniques.

anemia: a condition in which the body has a low number of red blood cells.

anesthesia: the use of medicine to prevent the feeling of pain or sensation during surgery or other procedures that might be painful.

anesthesiologist: a physician who specializes in giving and managing anesthetics, medications that numb an area of the body or help a person fall and stay asleep for surgical procedures or diagnostic tests. Anesthesiologists also help with the treatment and management of chronic pain.

angiogram: a type of X ray, using a special dye, that helps show blood vessels and blood flow. It's also used to identify certain kinds of tumors.

apheresis: a procedure that involves removing blood, separating it into plasma, platelets, and leukocytes, and removing the blood part that is causing a particular disease or condition. The remaining blood parts are then re transfused into the person.

aplastic anemia: occurs when the bone marrow can't make enough red blood cells. This can be due to a viral infection or exposure to certain toxic chemicals, radiation, or medications.

astrocyte: a cell located in the brain.

bilateral: found on both sides of the body; when referring to cancer, it means cancer found in paired organs (for example, in both kidneys).

biologic response modifiers: substances that help the immune system fight cancer, lessen side effects from cancer treatments, and fight infections and other diseases.

biologic therapy: see immunotherapy.

biopsy: the removal of a sample of tissue from the body for further examination. A biopsy gives doctors a closer look at what's going on inside to help make a diagnosis and choose the right treatment.

blast cell: an immature blood cell that grows into a red blood cell, white blood cell, or platelet.

blastoma: a type of cancer (specifically, a tumor) caused by blast cells.

blood: the naturally produced fluid in the body that is made up of red blood cells, which carry oxygen throughout the body; white blood cells, which fight infections; platelets, which help stop bleeding; and plasma, a yellowish liquid that carries nutrients, hormones, and proteins throughout the body.

blood banking: blood banks collect and store blood that healthy people donate. The bank keeps blood ready in case someone needs it because of an accident or surgery.

blood plasma: a yellowish liquid that carries nutrients, hormones, and proteins throughout the body.

bone marrow: a thick, spongy liquid inside the bones. Bone marrow makes all kinds of blood cells: red blood cells that carry oxygen, white blood cells that fight infections, and platelets that help blood clot.

bone marrow transplant (BMT): a procedure that involves replacing unhealthy bone marrow with healthy bone marrow cells from a donor.