acute leukemia
Meaning of acute leukemia: Immature blood cells fill the marrow, so the illness comes from what is missing rather than from what is present.
Definition of acute leukemia
Acute leukemia is a fast-growing cancer of the blood-forming cells in bone marrow, in which immature cells called blasts multiply and take over the space where normal blood cells are made. Because red cells, platelets and working white cells fall away, tiredness, bruising and infection appear within weeks. Untreated, it progresses quickly.
What goes wrong in the marrow?
Blood cells begin as stem cells in the bone marrow and mature through a series of steps before entering the circulation. In acute leukemia a cell early in that sequence acquires genetic changes that let it divide without limit and prevent it from maturing. The result is a mass of blasts, cells frozen in an immature state and unable to do any useful work. They fill the marrow and squeeze out normal production. The number of blasts reaching the bloodstream varies, so the white cell count may be high, normal or low, and it is the loss of everything else that causes the illness.
What symptoms does it cause?
| What is missing | Result |
|---|---|
| Red cells | Tiredness, breathlessness, pallor |
| Platelets | Bruising, nosebleeds, bleeding gums |
| Working white cells | Repeated or severe infection, fever |
Bone pain, night sweats, weight loss and swelling of lymph nodes or spleen occur as well. The pace is what marks it out, since symptoms build over days to weeks rather than over the months or years of a chronic leukemia.
What are the two main kinds?
Which cell line the blast came from determines the type, and the two behave differently. Acute lymphoblastic leukemia arises from the precursors of lymphocytes, is the commonest cancer of childhood, and responds well to treatment in that age group. Acute myeloid leukemia arises from the precursors of the other white cells, red cells and platelets, becomes steadily more frequent with age, and is the harder of the two to treat. Both are divided further by the genetic changes found in the leukemia cells, and those findings now guide treatment more than the appearance under the microscope does.
How is it diagnosed and treated?
A blood count and film raise the suspicion, and a marrow sample confirms it, with the cells tested for surface markers, chromosome changes and specific gene faults. Treatment is intensive chemotherapy given in phases, beginning with an attempt to clear the marrow of blasts and continuing with further courses aimed at preventing return. Some subtypes respond to targeted drugs, and a stem cell transplant is used where the risk of relapse is high.
Used in a sentence
The blood film showed circulating blasts, and marrow examination confirmed acute leukemia.
Good to know
The white cell count may be high, normal or low, so a normal count does not exclude acute leukemia, and the illness follows from the loss of normal blood cells rather than the excess of blasts.
Word origin
Where “acute leukemia” comes from
Leukemia comes from the Greek leukos, meaning white, and haima, meaning blood.