The doctor's mouth opens and the word falls out like a stone. It is the weight of the world and lands with full force on your heart, which has dropped to the floor. Leukemia. What does it mean?
What is Leukemia?
Leukemia is commonly known as cancer of the blood. While that is in fact a
correct definition, it would be more precise to call it a bone marrow disorder.
Leukemia occurs when one abnormal white blood cell begins to clone itself; the
clones do not fight infection properly, nor do they die at the same rate as
other white cells, which inhibits the reproduction of healthy cells.
Acute or Chronic?
The seven main types of leukemia are classified as either acute, which
progresses rapidly, or chronic, which progresses slowly. In acute leukemia,
there is an abnormal growth of immature cells called “blasts.” Chronic leukemia
is marked by some blast cells along with an excessive number of mature blood
cells.
Leukemia is also classified according to which type of white blood cell is
behaving strangely. When the lymphocytes are abnormal, it called lymphocytic or
lymphoblastic leukemia. Lymphocytes are one of the five kinds of white blood
cells (leukocytes) circulating in the blood. Mature lymphocytes look pretty
much alike, but have different functions.
The most abundant lymphocytes are B-lymphocytes and T-lymphocytes, commonly referred
to as B-cells and T-cells. B-cells are produced and grow to maturity in the
bone marrow, which is why they are assigned the letter “B.” T-cells originate
in the bone marrow but move on to acquire the letter “T” by maturing in the
thymus.
When myelocytes are abnormal, it is called myelocytic or granulocytic
leukemia. Myelocytes are also called granulocytes because of the granules found
inside the cell. Neutrophils, basophils, esoinophils, and monocytes (all types
of myelocytes) circulate through the blood, killing bacteria.
Acute and chronic leukemias are further subdivided into lymph-status
categories. Acute can be either acute lymphocytic leukemia (ALL) or acute
non-lymphocytic leukemia (ANLL). ANLL also includes other types of white cells,
such as melocytes (AML).
Chronic leukemias follow suit and become chronic lymphocytic leukemia (CLL)
or chronic myeloctyic leukemia (CML).