GLOSSARY OF TERMS
Glossary
Here you will find definitions and meanings of some of the most frequently used terms on the site.
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A basophil is a type of white cell that participates in certain allergic reactions.
Chemicals or structures present either on the surface of or within cells or in the serum. They may aid doctors in determining when treatment (and which type of treatment) is needed by identifying disease that will progress more rapidly and/or have a better or worse response to certain treatments.
Examples of biomarkers are gene expression, serum protein levels and chromosome Acute Myeloid Leukaemia abnormalities in cancer cells. No single feature can accurately predict disease progression in a patient; therefore, doctors use a combination of factors to make a diagnosis and a treatment plan. Biomarkers are also known as “cancer cell markers” and “tumour markers.”
A biopsy procedure is used to obtain tissue for diagnosis. In many cases, a special needle can be used to obtain the tissue. In some cases, a larger piece of tissue may be surgically removed. Since the appearance of a lymph node is important in categorizing the type of lymphoma that may be present, surgical removal of one or more entire, swollen lymph nodes may be necessary (lymph node biopsy). The tissue is placed in preservative, stained with dyes and examined under a microscope by a pathologist.
These are the earliest marrow cells identified by the light microscope. Blasts represent about 1 per cent of normally developing marrow cells. They are largely myeloblasts, which are cells that will develop into neutrophils. In normal lymph nodes, blasts are lymphoblasts; that is, cells that are part of lymphocyte development. In the acute types of leukaemia, blast cells similar in appearance to normal blast cells accumulate in large numbers, constituting up to 80 per cent of all marrow cells.
In myelodysplastic syndromes and acute myeloid leukaemia, myeloblasts accumulate, and in acute lymphoblastic leukaemia, lymphoblasts accumulate. Normal myeloblasts give rise to granulocytes (neutrophils, eosinophils and basophils). With myelodysplastic syndromes, abnormal myeloblasts displace or otherwise interfere with the production of normal red cells, white cells and platelets in the marrow.
Sometimes the distinction between myeloblasts and lymphoblasts can be made by examination of stained marrow cells through the microscope.
Often, immunophenotyping or use of specially stained marrow cells is required to be sure of the distinction.
A laboratory test requiring a small blood sample which can be used to measure the number and types of cells circulating in the blood. The term complete blood count or CBC, or full blood count FBC is often used to refer to this test.
Any of the three main types of cells in the blood: red cells, which carry oxygen; white cells, which principally prevent or combat infections; and platelets, which help prevent bleeding. There are several types of white cells in the blood. Each cell type is represented in blood in the numbers that meet the functions it serves.
One fluid ounce of blood contains about 150 billion red cells, 8 billion platelets, and 20 million white cells. Red cells live for months, platelets live for a week or two, and white cells live for a few days. The marrow must replace over 500 billion cells from the blood each day.
Bone Marrow is a spongy tissue in the hollow central cavity of the bones that is the site of blood cell formation. By puberty, the marrow in the spine, ribs, breastbone, hips, shoulders and skull is most active in blood cell formation.
In adults, the bones of the hands, feet, legs and arms do not contain blood-forming marrow. In these sites the marrow is filled with fat cells. When marrow cells have matured into blood cells, they enter the blood that passes through the marrow and are carried throughout the body.
A test to examine marrow cells to detect cell abnormalities. A marrow sample is usually taken from the patient’s hip bone. After medication is given to numb the area, the liquid sample is removed using a special needle inserted through the bone and into the bone marrow. The sample is looked at under a microscope for abnormal cells. The cells obtained can also be used for cytogenetic analysis and other tests.
This is a test to examine marrow cells to detect cell abnormalities. This test differs from a bone marrow aspiration in that a small amount of bone filled with marrow is removed, usually from the hip bone. After medication is given to numb the area, a special biopsy needle is used to remove a core of bone containing marrow. The marrow is examined under a microscope to determine if abnormal cells are present. Bone marrow aspiration and biopsy may be done in the doctor’s office or in a hospital. The two tests are almost always done together. Both tests are also done after treatment to determine the proportion of blood cancer cells that have been killed by therapy.