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Childhood Leukemia

Glossary of Terms

The following material is taken from Childhood Leukemia: A Guide for Families, Friends, and Caregivers, 2nd Edition by Nancy Keene, copyright 1999 by O'Reilly & Associates, Inc. For book orders/information, call (800) 998-9938. Permission is granted to print and distribute this excerpt for noncommercial use as long as the above source is included. The information in this article is meant to educate and should not be used as an alternative for professional medical care.


Absolute neutrophil count (ANC); also known as absolute granulocyte (AGC)
Total count of the neutrophils in the blood, which provides an indication of a person's ability to fight infection. To calculate the ANC, add the percentages of seg neutrophils and band neutrophils, divide by 100, and multiply by the total white blood count.

ALL (acute lymphoblastic leukemia)
An acute form of leukemia occurring predominantly in children, characterized by the unrestrained production of immature lymphoblasts (a type of white cell) in the blood-forming tissues, particularly the bone marrow, spleen, and lymph nodes.

AML (acute myeloid leukemia)
An acute form of leukemia characterized by a massive proliferation of mature and immature abnormal granulocytes (a type of white cell).

Allogeneic transplant
Type of bone marrow transplant in which the marrow is donated by another person.

Hair loss; a common side effect of chemotherapy.

Condition in which there is a reduction in the number of circulating red blood cells.

Partial or total loss of sensation, with or without loss of consciousness, induced by the administration of a drug.

Loss of appetite.

A doctor who specializes in the study and administration of anesthesia.

Attending physician
Doctor on the staff of a hospital who has completed medical school, residency, and fellowship.

Acute lymphoblastic leukemia (ALL)
An acute form of leukemia occurring predominantly in children, characterized by the unrestrained production of immature lymphoblasts (a type of white cell) in the blood-forming tissues, particularly the bone marrow, spleen, and lymph nodes.

Without symptoms.

From the same person. An autologous bone marrow transplant is a procedure in which bone marrow that has been removed from a patient is given back to that patient.

B cells
Type of lymphocyte (white cell) that helps produce antibodies that destroy foreign substances.

Type of granulocyte (white cell) that plays a special role in allergic reactions and helps in the healing of inflammations.

Blast cell
An undifferentiated normal cell in an early stage of development; also means a leukemic cell of indeterminable type.

Blood-brain barrier
A network of blood vessels located around the central nervous system with very closely spaced cells that make it difficult for potentially toxic substances-including anticancer drugs-to enter the brain and spinal cord.

Blood type
Identification of the proteins in a person's blood cells so that transfusions can be given with compatible blood products. Examples of blood types are A+, A-, B+, B-, AB+, AB-, O+, O-.

Bone marrow
Soft, inner part of large bones that makes blood cells.

Bone marrow aspiration
Process in which a sample of fluid and cells is withdrawn from the bone marrow using a hollow needle.

Bone marrow biopsy
The removal of a sample of solid tissue from the bone marrow.

Bone marrow transplant
A procedure in which doctors replace bone marrow that has been destroyed by high doses of chemotherapy and/or radiation.

CBC (complete blood count)
Measurement of the numbers of white cells, red cells, and platelets in a cubic millimeter of blood.

CML (chronic myelogenous leukemia)
A disease that progresses slowly and is characterized by increased production of granulocytes in the bone marrow. It is usually associated with a specific chromosomal abnormality called the Philadelphia chromosome.

CNS (central nervous system)
The brain, spinal cord, and nerves.

A term for diseases in which abnormal cells divide without control.

A substance or agent that produces cancer.

Measurement of radiation-absorbed dose; same as a rad.

Central nervous system
Brain, spinal cord, and nerves.

Cerebrospinal fluid (CSF)
Fluid that surrounds and bathes the brain and spinal cord and provides a cushion from shocks.

Children's Cancer Group (CCG)
An organization that designs and monitors pediatric clinical trials.

Treatment of disease with drugs. The term usually refers to cytotoxic drugs given to treat cancer.

A structure in the nucleus of a cell that contains genetic material. Normally, 46 chromosomes are inside each human cell.

Chronic myelogenous leukemia (CML)
A disease that progresses slowly and is characterized by increased production of granulocytes in the bone marrow. It is usually associated with a specific chromosomal abnormality called the Philadelphia chromosome.

Clinical trial
A carefully designed and executed investigation of a drug, drug dosage, combination of drugs, or other method of treating disease. Each trial is designed to answer one or more scientific questions and to find better ways to prevent or treat disease.

Portion of the protocol which consists of new combinations of drugs to destroy any cancer cells that survived induction.

Cytomegalovirus (CMV)
One of a group of herpes viruses that can cause fatal infections in immunosuppressed patients.

Causing the death of cells.

Delayed intensification
Portion of treatment that comes after the initial induction, consolidation, and interim maintenance. The purpose of this phase is to destroy any remaining cancer cells.

The process by which cells mature and become specialized.

A diagnostic test that uses ultrasound to visualize the interior of the heart and determine how effectively it is functioning.

Electrocardiogram (ECG, EKG)
A graphic record of the electric current produced by the contraction of the heart.

Electromagnetic fields
Magnetism produced by electrical fields.

A type of white cell that responds to allergic reactions as well as foreign bacteria.

Red blood cells.

External catheter
Indwelling catheter in which one end of the tubing is in the heart and the other end of the tubing sticks out through the skin.

A physician who has completed four years of medical school and several years of residency, and is pursuing additional training in a specialized field.

Finger poke
When a laboratory technician pricks the fingertip to obtain a small sample of blood.

Tissue taken from one person (donor) and transferred to another person (recipient or host).

Graft-versus-host disease
A condition that may develop after allogenic bone marrow transplantation in which the transplanted marrow (graft) attacks the patient's (host's) organs.

A type of white cell that destroys foreign substances in the body such as viruses, bacteria, and fungi.

Inflammation of the liver by virus or toxic origin. Fever and jaundice are usually present, and sometimes the liver is enlarged.

The measurement of the proportion of cells to plasma in a sample of blood. Sometimes called packed cell volume (PCV).

Physician who specializes in the diagnosis and treatment of disorders of blood and blood-forming tissues.

The protein found in red blood cells that carries oxygen.

Hemorrhagic cystitis
Bleeding from the bladder, which can be a side effect of the drug cytoxan.

Heparin solution
An anticoagulant injected into indwelling catheters between uses to prevent clots.

HIV (human immunodeficiency virus)
The virus that causes AIDS.

In bone marrow transplantation, the person who receives the marrow.

Human leukocyte antigens (HLAs)
Proteins on the surface of cells that are important in transplantation and transfusion. For BMTs, the HLAs on white cells of the patient and potential donor are compared. A perfect HLA match occurs only between identical twins.

Infusion pump
A small, computerized device which allows drugs to be given at home through an IV or indwelling catheter.

Immune system
Complex system by which the body is able to protect itself from foreign invaders.

When the immune system is suppressed, leaving the body susceptible to infection.

The first part of the chemotherapy protocol for treating some types of leukemia in which several powerful chemotherapy drugs are given to kill as many cancer cells as possible.

Institutional Review Board (IRB)
Group made up of scientists, clergy, doctors, and citizens from the community, which approves and reviews all research taking place at an institution.

Recent medical school graduate who is receiving his/her first year of supervised practical training in medical and surgical care of patients in hospitals.

Injecting drugs into the cerebrospinal fluid during a spinal tap.

Intravenous-access line (IV)
A hollow metal or plastic tube which is inserted into a vein and attached to tubing, allowing various solutions or medicines to be directly infused into the blood.

Disease characterized by the unrestrained growth of abnormal white cells in the bone marrow, and often in the spleen and liver; these cancerous cells usually appear in the peripheral blood and may also invade other organs.

White blood cells.

A below-normal number of white cells.

Drug most commonly used for local anesthesia.

Lumbar puncture (LP; spinal tap)
Procedure in which a needle is inserted between the vertebrae of the back to obtain a sample of cerebrospinal fluid and/or inject medication.

A clear, colorless fluid found in lymph vessels throughout the body, which carries cells to fight infection.

Lymph nodes
Rounded bodies of lymphatic tissues found in lymph vessels.

Lymph system
A system of vessels and nodes throughout the body which helps filter out bacteria as well as performs numerous other functions.

Type of white cell, formed in the lymphoid tissues, that prevents infection and helps provide immunity to disease.

Part of a leukemia protocol for treating ALL. It follows the intensive induction and consolidation phases and helps destroy any remaining cancer cells.

Medical student
Student who has completed four years of college and is enrolled in medical school.

Type of white blood cell.

Substance which is poisonous to the brain, spinal cord, and/or nerve cells.

Condition when the body does not have enough neutrophils (a type of infection-fighting white cell).

The most numerous of the granulocytic white cells, which migrate through the bloodstream to the site of infection, where they ingest and destroy bacteria.

A professional who analyzes nutritional requirements and gives advice on how to eat an appropriate diet for any condition.

Doctor who specializes in the treatment of cancer.

Study of cancer.

A gland situated behind the stomach which has two vital functions: it secretes enzymes into the intestines which aid in the digestion of food, and it produces and secretes insulin, a hormone essential for regulating carbohydrate metabolism by controlling blood sugar levels.

Inflammation of the pancreas which can cause extreme pain, vomiting, hiccoughing, constipation, and collapse.

Doctor who specializes in examining tissue and diagnosing disease.

Doctor who specializes in the care and development of children and the treatment of their diseases.

Pediatric Oncology Group (POG)
An organization which designs and monitors pediatric clinical trials.

Small, reddish spots under the skin caused by hemorrhage.

The liquid part of the lymph and the blood.

Disc-shaped blood cell which aids in blood clotting.

Indwelling catheter which has a small portal under the skin of the chest attached to tubing which goes into the heart.

Expected or probable outcome.

An attempt to prevent disease.

The "recipe" for a child's cancer treatment. Outlines the drugs that will be taken, when they will be taken, and in what dosages. Also includes the dates for procedures (e.g., bone marrow aspiration schedule).

Radiation absorbed dose. A unit of measurement of the absorbed dose of radiation.

High-energy rays which are used to kill or damage cancer cells.

Doctor who specializes in using radiation and radioactive isotopes to diagnose and treat disease.

Chosen at random. In a randomized research project, a computer chooses which patients receive the experimental treatment(s) and which patients receive the standard treatment.

A return of the cancer after its apparently complete disappearance.

Disappearance of detectable disease.

Physician who has completed four years of medical school and one year of internship, and who is continuing his or her clinical training.

Right atrial catheter
Indwelling catheter with tubing that extends into the heart which provides access for drawing blood and injecting medication.

Side effect
Unintentional or undesirable secondary effect of treatment.

Somnolence syndrome
Syndrome which can occur from three to twelve weeks after cranial radiation. It is characterized by drowsiness, prolonged periods of sleep (up to twenty hours a day), low-grade fever, headaches, nausea, vomiting, irritability, difficulty swallowing, and difficulty speaking.

Spinal tap
Procedure in which a needle is inserted between the vertebrae of the back to obtain a sample of cerebrospinal fluid and/or inject medication. Also called a lumbar puncture (LP).

Staphylococcus epidermidis
Bacteria normally present on the skin which can infect the blood through an indwelling catheter.

Stem cells
Cells from which all blood cells develop.

Enzyme sometimes used to dissolve blood clots in catheter tubing.

Loss of consciousness and paralysis caused by bleeding into the brain or clotting that blocks blood flow to a portion of the brain, causing injury or death to brain tissue.

Subcutaneous port
Type of indwelling catheter comprised of a portal under the skin of the chest attached to tubing leading into the heart.

Affecting the body as a whole.

T cell
Type of lymphocyte (white cell), derived from the thymus, that attacks infected cells, foreign tissue, and cancer cells.


Small gland located behind the breast bone and between the lungs that plays a major role in the immune system.

Tumor board
A meeting held at a hospital, attended by oncologists, pathologists, radiologists, fellows, and residents, where complicated cases are discussed to develop a treatment plan.

Enzyme sometimes used to dissolve clots in catheter tubing.

Antibiotic commonly used to treat infections in indwelling catheters.

Vital signs
Term that describes a patient's pulse, rate of breathing, and blood pressure.

White blood cells
Cells that help the body fight infection and disease.

High-energy electromagnetic radiation used in low doses to diagnose disease or injury and in high doses to treat cancer.

X-ray technician
Certified technician who positions patients for x-rays, monitors equipment, and takes x-rays of the body

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