Glossary of common blood cancer terms

You’ll find commonly used blood cancer and blood disorder terms, and their definitions, on this page. You can click through each letter in the A-Z index, or type in a word or phrase in the search bar below then click ‘Search the Glossary’.

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• ablative therapyHigh dose chemotherapy or radiotherapy aimed at destroying any residual cancer cells but which at the same time destroys the patient’s own bone marrow and therefore requires stem cell rescue
• abnormalitiesDifferent from the normal.
• acute lymphoblastic leukaemiaA rapidly progressive cancer of the blood, usually of sudden onset, and characterised by the uncontrolled growth of immature blood cells which take over the bone marrow and spill into the bloodstream. If left untreated, it is fatal within a few weeks or months.
• acute myeloid leukaemiaA rapidly progressing cancer of the blood affecting immature cells of the bone marrow, usually of the white cell population. It is more common in adults than in children.
• adenosine deaminase inhibitorsDrugs used in the treatment of chronic lymphocytic leukaemia and lymphoma that appear to be less toxic because they act by encouraging cell death rather than actively killing cells. They may be more effective in some diseases than more conventional chemotherapy.
• aetiologyThe scientific study of the factors that cause a disease, for example, environmental factors such as infections and radiation.
• alkylating agentAnti-cancer drugs that interact with genetic material (DNA) in such a way as to prevent division of the cells. Drugs of this type include busulphan, chlorambucil, cyclophosphamide, and melphalan.
• allogeneic stem cell transplant(Also called a bone marrow transplant) A stem cell transplant using marrow collected from a matched healthy donor, usually a brother or sister. The risk associated with such a transplant increases with age.
• alopeciaThe loss of hair. A side-effect of some forms of chemotherapy or radiotherapy used to treat leukaemia and other cancers. Usually temporary.
• amyloidAn abnormal, insoluble protein, which deposits in organs and tissues of the body.
• anaemiaA lower-than-normal number of red blood cells in the blood. It causes tiredness, paleness, and sometimes shortness of breath.
• anthracyclinesDrugs used in leukaemia therapy to prevent cell division by disrupting the structure of DNA. Drugs of this type include daunorubicin, doxorubicin (adriamycin), epriubicin, and idarubicin.
• anti-emeticA drug to prevent or alleviate nausea and vomiting that can sometimes be a side-effect of chemotherapy. Drugs of this type include metoclopramide (maxolon), zofran (ondansetron).
• anti-fungalA drug used to treat fungal infections.
• anti-viralA drug used to treat viral infections.
• antibioticsDrugs that kill or stop the growth of bacteria, for example, penicillin.
• antibodiesNaturally produced substances in the blood that destroy or neutralise specific toxins or foreign bodies, for example, viruses. They are produced by the white blood cells known as lymphocytes in response to exposure to the antigens of the foreign body against which they act. They form an(…)
• antigenA substance, usually on the surface of foreign body such as a virus or bacteria that stimulates cells of the body’s immune system to react against the antigen by producing antibodies.
• antihistaminesDrugs given to diminish allergic reactions.
• antilymphocyte globulinAntibodies that attach to and destroy lymphocytes. This may be used clinically by injection into a vein, for example, in aplastic anaemia or in other conditions where the body’s immune system is being harmful. (See also auto-immune diseases.)
• antimetabolitesA group of anti-cancer drugs that prevent cells growing and dividing by blocking the chemical reactions required in the cell to produce DNA. Drugs of this type include mercaptopurine, azathioprine, thioguanine, and methotrexate.
• apheresisFrom the Greek ‘aphairesis’ meaning ‘removal’. The process of ‘skimming off’ the stem cells from the blood to be used for transplant or stored in frozen form until needed. This occurs through an apheresis machine that filters the blood, gradually separating and collecting the stem cells and(…)
• aplastic anaemiaA rare disorder characterised by failure of the bone marrow to produce blood cells, as opposed to leukaemia where cells are produced but do not mature. It may occur as an inherited condition (see Fanconi’s anaemia) or, more often, the disease develops in later life, the cause of which may or(…)
• audiogramHearing test charted for different frequencies. Usually used for early detection of drug toxicity to the nerve controlling hearing.
• Auer rodsLook like thin red or purple lines or needle-shaped rods, are found inside some white blood cells. Healthy blood cells don’t usually contain them.
• auto-immune diseaseA disease caused by an individual’s immune system producing antibodies against tissues of its own body. The type of antibody so produced must have an adverse effect in the body, as some antibodies are necessary for normal function. Examples include some haemolytic anaemia, rheumatoid arthritis(…)
• autologous stem cell transplantA bone marrow transplant using stem cells taken from the patient’s own bone marrow. These stem cells are collected and stored at an early disease stage or after treatment that has not controlled the disease. The marrow may be manipulated in the laboratory to try to reduce the risk of(…)
• B cell (B lymphocyte)A type of white blood cell normally involved in the production of antibodies to combat infection. The mature B cell is often called a plasma cell. An antibody ‘sticks’ to an antigen on a foreign cell, causing the antibody-antigen cell to be destroyed or to break down. Tumours of mature B cells(…)
• bacteriaMicroscopic organisms which cause many types of infectious disease, for example pneumonia. The reduced ability of patients to fight infections following chemotherapy or bone marrow transplantation means that even normally harmless bacteria existing, for example, on the skin or mouth, may cause(…)
• baselineA first measurement of a condition taken early on, used to compare over time to look for changes.
• basophiliaAn increase in the number of basophils in the blood.
• basophilsA type of white blood cell that fights infection.
• Bence-Jones proteinA characteristic protein found in the urine of some patients with multiple myeloma. It is derived from the antibody produced by myeloma cells and can be used to help in diagnosis of the disease and to monitor the effects of treatment. The amount of BJP in the urine may reflect the amount of(…)
• benignNon-cancerous. Such a growth may or may not need to be surgically removed.
• Beta-2 microglobulinA protein found on the surface of many cells including white blood cells. A very high level of beta-2 microglobulin in the blood at diagnosis of myeloma may indicate more advanced disease and a poorer prognosis.
• biopsyA small sample of fresh tissue, for example, lymph node or bone marrow, removed for laboratory analysis to establish exact diagnosis.
• biotherapyThe treatment of disease through the use of natural living processes.
• bisphosphonatesA drug used to prevent or slow down bone damage, and treat high calcium levels in the blood. It is used to treat, strengthen bones and prevent fractures in some types of cancer.
• blast cellsImmature blood cells normally in the bone marrow in small numbers.
• blastsImmature blood cells normally in the bone marrow in small numbers.
• blood cellsThere are three main types of cells in the bloodstream – the red blood cell, which carries oxygen, the white blood cell, which fights infection, and the platelet, which helps prevent bleeding. The correct balance between each cell type must be maintained for the body to remain healthy.
• blood countA routine test requiring a small blood sample to estimate the number and type of cells circulating in the blood.
• blood diseaseThis is a misleading term, for although malignant cells are often found in the blood, they do not originate there. Diseases are classified by their origin eg. lymphoma, from lymph gland.
• bone marrowSoft, sponge-like tissue in the centre of most bones. It contains stem cells that make all blood cells.
• bone marrow aspirateA sample of bone marrow fluid.
• bone marrow biopsyA procedure to collect and examine bone marrow.
• bone marrow transplantA procedure which replaces blood stem cells in people whose bone marrow has been destroyed by chemotherapy and/or radiotherapy.
• bone marrow trephineA sample of bone marrow tissue.
• brachytherapyA means of delivering radiotherapy directly to a tumour by an implanted tube. It avoids the use of external beams of radiation and often allows stronger treatment without an increase in toxicity.
• Burkitt’s lymphomaA rapidly growing type of non-Hodgkin’s lymphoma. First described in Africa where it may present as a cancer of the facial bones. However, in other countries it more usually affects the abdomen. It requires immediate treatment and is uncommon in western countries.
• C-reactive protein (CRP)A protein released by the liver in response to inflammation in the body. Level of CRP may be elevated in advanced myeloma.
• cancerA disease resulting from abnormal cells growing in an uncontrolled way.
• cannulaA plastic tube which can be inserted into a vein to allow fluid to enter the blood circulation.
• carcinogenA substance that may have the ability to cause cells to become cancerous. The best known example is the relationship between cigarette smoking and lung cancer. Not all cancers have recognised carcinogens as a cause or high risk.
• carcinogenesisThe development of cancer.
• cardiacRelated to the heart.
• catheterA hollow tube inserted into organs of the body for admitting or removing gases or liquids. For example, for the removal of urine from the bladder.
• CD 34 cellsNumber allocated to the population of cells in the blood and marrow which contain most of the stem cells used in transplant. A ‘CD 34 count’ is used to measure a patient’s readiness to have cells collected after mobilisation.
• cell biologyThe study of the structure, composition and function of cells.
• cell markersBiochemical or genetic characteristics that distinguish and discriminate between different cell types. They are like flags stuck to the outside of a cell which can be analysed in special machines.
• cellsThe individual units from which tissues of the body are formed. They are not visible to the naked eye, but can be seen under the microscope and can be grown in culture.
• central nervous system (CNS)The brain and spinal cord.
• central venous catheter (CVC)Also known as a central venous access device (CVAD). A line tube passed through the large veins of the arm, neck, chest or groin and into the central blood circulation. It may be used for taking samples of blood, giving intravenous fluids, blood, chemotherapy and other drugs without the need(…)
• cerebrospinal fluid (CSF)Fluid that surrounds and protects the brain and spinal cord. Samples can be obtained by lumbar puncture and chemotherapy also can be injected by the same route.
• chemotherapyThe use of drugs to treat cancer
• chromosomePart of a cell that contains genetic information.
• chronic leukaemiaA persistent cancer of the blood, usually of gradual onset and generally of slow progression. May be diagnosed by chance following a routine blood test and before clinical symptoms appear. The leukaemia is usually called chronic because the leukaemic cells are more mature than acute leukaemia cells.
• chronic lymphocytic leukaemia (CLL)A slowly progressing form of leukaemia characterised by an increased number of the type of white blood cells known as lymphocytes. It is the most common form of leukaemia and occurs predominantly in late middle age onwards. It has variable symptoms and unknown cause but may be diagnosed by(…)
• chronic myeloid leukaemia (CML)A leukaemia which is initially slow progressing.It is characterised by the presence of large numbers of abnormal mature granulocytes circulating in the blood. Often referred to as chronic granulocytic leukaemia (CGL) and typically will transform over time into acute leukaemia.
• chronic myelomonocytic leukaemia (CMML)A form of myelodysplasia characterized by an increase in the number of circulating white blood cells of monocyte type. It may transform into acute leukaemia or patients may develop problems with infection or bleeding.
• clinical haematologistA specialist trained as a physician and pathologist to diagnose and treat diseases of the blood, marrow and lymph glands, e.g. the person who normally diagnoses and treats leukaemia, lymphoma and myeloma.
• clinical trialA controlled and carefully monitored assessment of new forms of treatment. Trials can vary in design and size from small-scale trials of experimental treatments to large national trials that compare subtle variations in current therapies. The patient will be informed and will always be given(…)
• cloneA population of genetically identical cells arising from a single parent cell. Leukaemia is believed to be a clonal disease, that is, all the leukaemia cells may originate from one abnormal cell.
• clottingA process where blood changes into a solid state.
• clotting factorsA group of chemical constituents of the fluid part of the blood (factors I to XIII) which interact to make blood clot.
• CNS leukaemiaInvasion of the brain, central nervous system, or spinal cord by leukaemic cells. This may be diagnosed by examination of cerebrospinal fluid obtained by a lumbar puncture.
• coagulationProcess of changing from a liquid blood to a solid. Also called clotting. Platelets help with coagulation.
• coagulationClotting of the blood. A complex reaction depending on a series of biochemical components and platelets in the blood.
• ‘Common’ acute lymphoblastic leukaemia (cALL)A sub-type of acute lymphoblastic leukaemia affecting cells early in the B lymphocyte family which accounts for about 80 per cent of all acute lymphoblastic leukaemias.
• complete remissionWhen anti-cancer treatment has been successful and so much of the disease has been destroyed that it can no longer be detected using current technology. In people with leukaemia this means that proportion of blast cells in the marrow has been reduced to less than five per cent. There are no(…)
• congenitalA condition present at birth.
• consolidation treatmentA course of treatment with anti-cancer drugs given to the patient while in remission, with the aim of killing any remaining small number of cancerous cells.
• contagiousA disease spread from person to person.
• cord bloodThe blood contained in the umbilical cord and placenta at birth. This blood contains a rich supply of blood stem cells. These stem cells have the capacity to repopulate the bone marrow spaces and produce blood cells. Cord blood can be collected through a cord blood banking program. The(…)
• cord blood transplantThe use of donated cord blood as part of an allogeneic transplant.
• corticosteroidsA group of synthetic hormones including prednisone,prednisolone, methylprednisolone and dexamethasone used in the treatment of some leukaemia and also to suppress graft rejection and graft-versus-host disease following bone marrow transplant. Side-effects include an increased risk of(…)
• covidAn infectious disease caused by the SARS-CoV-2 virus.
• creatinineA waste product of muscle breakdown normally excreted by the kidneys. The level of creatinine in the blood will be raised if the kidneys are not functioning properly.
• cryopreservationThe storage of blood stem cells at a very low temperature. The technique used does not harm the stem cells and ensures that they remain intact and functional when they are thawed out months and even years later.
• CT scanComputer assisted tomography (CAT) is a complex x-ray technique used to produce serial detailed internal images of any part of the body. The patient lies on a couch, which gradually moves through the X-ray machine, and the image is built up by a computer as a cross-section of the body. It is a(…)
• cureThis means that there is no evidence of disease and no sign of the disease reappearing, even many years later.
• cyclosporinA drug used to prevent and treat rejection and graft-versus-host disease in transplant patients by suppressing their normal immune system.
• cytogenetic changesAbnormal structure and function of cells, particularly chromosomes, found through studying cells.
• cytogenetic testsThe study of cells to identify changes in chromosomes.
• cytomegalovirus (CMV)A virus which is usually harmless in healthy people but may cause serious disease in immunosuppressed patients. Particularly dangerous following a bone marrow transplant.
• cytopeniaWhere there is a lower-than-normal number of a type of blood cell in the blood.
• cytoplasmThe jelly-like substance inside each cell.
• cytotoxic drugsAnti-cancer drugs that act by killing or preventing the division of cells.
• defectsAn abnormality.
• deletionMissing a portion of the chromosome.
• dendritic reticulin cells (DRC)Cells of bone marrow origin whose job is to present antigens from foreign agents to the immune cells to allow the development of immunity. These cells may one day be used in therapy to enhance the immune system against cancer cells
• depletionA laboratory procedure for reducing the number of specific cell types within bone marrow donated for transplantation, for example, the removal of some types of lymphocytes to avoid mismatch problems (particularly in relation to unrelated donor transplants) or to remove a sub-set of potentially(…)
• differentiationThe gradual maturation of a cell whereby its functions and properties become increasingly specialised. Leukaemic cells often are poorly differentiated, that is, show immature characteristics. The more a cell is differentiated, usually the less able it is to divide.
• disseminated diseaseDisease in which the cancerous cells have spread from the tissue of origin into several other organs.
• DNA (Deoxyribonculeic acid)Provides the essential building block for storing genetic material in ‘tapes’ or chromosomes. There are four different chemical compounds of DNA (bases) arranged in coded sequence as genes that determine an individual’s inherited characteristics.
• dysplasiaAlso called dysplastic cells. A change in size, shape, and arrangement of normal cells seen under a microscope.
• ECG (echocardiogram)A recording of the electrical signals in the heart.
• electroencephalogram (EEG)Electrical brain recording.
• electrolytesVarious salts in the blood. Measurement helps to monitor kidney function.
• embolusA blood clot that starts in the leg or other distant vein or artery, which breaks loose only to lodge elsewhere in the body and block blood supply. For example, a clot in a vein may cause a problem in the lung (pulmonary embolism).
• enzymeA complex protein found in the body.
• eosinophiliaIncreased numbers of eosinophils circulating in the blood. It occurs occasionally in some cases of Hodgkin’s disease, in drug reactions, in asthma, hay fever and parasitic infections.
• eosinophilsA type of white blood cell.
• epidemiologyThe science of studying the occurrence of disease in populations and relating this to genetic and/or environmental causes. This is not a very precise science as yet because of difficulty in collecting and collating disease data.
• Epstein Barr virusA common virus which causes glandular fever. Also associated with Burkitt’s lymphoma. Epstein and Barr first described this virus.
• erythrocytesA red blood cell that contains haemoglobin.
• erythroleukaemiaA rare cancer of the blood affecting immature red blood cells, e.g. acute erythroleukaemia which is a type of myeloid leukaemia.
• essential thrombocythemiaA condition caused by abnormal marrow growth (myeloproliferative disease) related to polycythemia rubra vera. The disease occurs when part of the bone marrow produces cells normally but they do not mature. It is characterised by the production of large numbers of platelets. Symptoms include(…)
• Fanconi’s anaemiaA rare inherited type of aplastic anaemia which carries an increased risk to the patient of developing leukaemia. May be treated by bone marrow transplant.
• full blood countA test that looks at the number, types and sizes of blood cells.
• G-CSF (granulocyte-colony stimulating factor)A naturally occurring and man-made growth factor which stimulates bone marrow’s stem cells to produce more white cells, particularly neutrophils.
• gallium scanA way of looking at the spread of lymphoma by injecting a dye that is taken up by active lymph glands. A way of staging lymphoma and Hodgkin’s disease. This test takes a couple of days to read.
• gamma globulinA concentrated solution of the antibody fraction of human blood given through the vein to fight infections, for example, measles in patients with low resistance. Gamma globulin is a very important by-product from blood donations.
• genesThe study of inherited characteristics.
• graft-versus-host disease (GvHD)A common, and sometimes serious, complication of allogeneic stem cell transplantation. Some of the donor’s immune cells try to reject the patient’s own cells as foreign. The skin, liver and gut may be affected. It can occur in either chronic or acute forms and is treatable by immunosuppressive(…)
• granulocyteA type of white blood cell containing granules in its cytoplasm (e.g. neutrophil, eosinophil, basophil). They protect the body against infection by seeking out and killing micro-organisms. Neutrophilic granulocytes are commonly called neutrophils.
• growth factorsProteins that control cell division and cell survival. Some are made in the lab and used as treatments, such as filgrastim.
• growth hormoneA biochemical secreted by the pituitary gland in the brain which controls growth and is particularly important during adolescence. Radiotherapy given to the head and neck of children with leukaemia may lead to a deficiency in growth hormone. This may be replaced by intramuscular injections.
• haematocritThe amount of blood that is made up of red blood cells.
• haematologistA doctor who specialises in diagnosing and treating blood disorders.
• haematologyThe study of blood diseases including leukaemia.
• haemoglobinA protein inside red blood cells that carries oxygen around the body.
• haemopoiesisThe formation of new blood cells.
• hepatomegalyEnlargement of the liver.
• hickman catheterA narrow plastic tube inserted through the skin, under anaesthetic, into a major blood vessel in the chest. It is used for patients undergoing intensive therapy and provides a route for taking blood samples and the administration of drugs without repeated needle puncture of a vein. It may have(…)
• hypogammaglobulinaemiaA problem with the immune system which prevents it from making proteins that help fight infection.
• immune systemThe body’s defence system against infection and disease.
• immunoglobinsProteins in the blood plasma which function as antibodies and play an important part in controlling infections. Some new therapies of synthesised antibodies are useful in controlling lymphoma without chemotherapy.
• immunosuppressionA treatment induced reduction in the body’s defence mechanisms. Deliberate immunosuppression is a necessary part of the bone marrow transplant procedure to prevent graft-versus-host disease and graft rejection.
• immunotherapyA treatment of disease which uses the body’s own immune system.
• inheritedA disease or trait passed down from parents.
• intravenousinto a vein
• karyotypeAnalysis to check the number, form and structure of chromosomes. This can give valuable information to aid in the diagnosis and the selection of treatment.
• late effectsSide-effects of chemotherapy and/or radiotherapy which only become apparent with long-term monitoring of the patient over a period of years. These are of particular concern in patients treated before puberty.
• leukaemiaCancer of the blood forming tissues resulting in large numbers of abnormal cells in the blood.
• leukocytesWhite blood cells which protect the body from infection and disease.
• lumbar punctureA procedure for removing fluid from around the spinal cord using a fine needle in the lower part of the back. Samples are analysed for evidence of any infection or CNS leukaemia. Also used to administer anti-cancer drugs either to prevent or cure CNS disease.
• megakaryocytesVery large bone marrow cells that break apart to form platelets.
• mgusMonoclonal Gammopathy of Undetermined Significance. It occurs when abnormal proteins are produced by the plasma cells.
• monocytesA type of scavenger cell that removes dead tissue.
• mononclonal antibodiesHighly specific antibodies produced by cells grown in the laboratory. Current research is investigating their clinical application for targeted delivery of drugs to leukaemia cells. Some antibodies against lymphoma have been developed which are directly toxic to lymphoma cells.
• morphologicallyHow the cells look under the microscope.
• mutationA harmful change in ‘normal’ DNA (the building blocks of all cells).
• neutropeniaA lower-than-normal number of neutrophils in the blood. It increases the risk of infection.
• neutrophilsThe most common type of white blood cell. They help fight infection.
• oncogenesGenes with the potential to cause cancer.
• oncologistGeneral term for a specialist who treats cancer. e.g. medical, surgical, radiation oncologist.
• pancytopeniaWhere there are lower-than-normal numbers of a type of all blood cells and platelets in the blood.
• pathologyThe study of disease, particularly of the structural tissue abnormalities produced by disease.
• PET scanA special type of radiological examination which appears to have the capacity to distinguish between cancerous and non-cancerous tissue deep in the body. It also is able to detect smaller sized tumours than CT scans.
• petechiaeTiny, unraised, round red spots under the skin caused by bleeding.
• PICC linePeripherally inserted central venous catheter (see central venous catheter). It is inserted in the middle of the forearm. PICCs are sometimes used for people having chemotherapy.
• plateletsAlso called thrombocytes. Tiny pieces of cells (megakaryocytes) found in the blood and spleen. They help form blood clots (coagulation) to slow or stop bleeding and to help wounds heal.
• prognosisAn estimate of the likely course and outcome of a disease.
• purpuraBleeding and bruising under the skin.
• radiotherapyHigh energy radiation that destroys cancer cells.
• red blood cellThe red cell in blood that contains the protein haemaglobin and carries oxygen around the body.
• relapseReturn of the original disease after it has improved for a time.
• remissionWhen the signs and symptoms of cancer have decreased or are undetectable.
• rigorA feeling of cold with shivers and shakes and a high temperature.
• stem cell transplantA procedure which replaces blood stem cells in people whose bone marrow has been destroyed by large doses of chemotherapy and/or radiotherapy.
• stem cellsYoung blood cells that provide new blood cells to replace those that are damaged or lost.
• subcutaneousunder the skin
• subcutaneous injectionAn injection into tissue immediately under the skin.
• T cell(T lymphocyte). A type of white blood cell derived from the thymus (hence T cells) involved in controlling immune reactions. Uncontrolled growth of this type of cell gives rise to T cell leukaemia/lymphoma.
• thrombocytesCell fragments in the blood that form clots and stop bleeding, also called platelets.
• thrombocytopeniaA lower-than-normal number of platelets in the blood. It causes bruising and bleeding.
• tomographySerial X-ray pictures of internal organs of the body. CT scanning is a special type of tomography.
• tumourAn accumulation of abnormal cells which may be benign or malignant.
• virologyThe study of viruses and viral diseases.
• virusA minute infective agent which depends on the cell it infects for its replication and survival. Sometimes, it behaves like a ‘wild gene’ and attaches to the genetic code.
• white blood cellsCells which protect the body from infection and disease, also called leukocytes.
• x-raysA form of radiation used both in diagnosis and treatment.
• zoster immune globulin (ZIG)Gamma globulin directed specifically against chicken pox, which sometimes can be given to an immuno-suppressed patient following direct contact with the disease to prevent infection.