Leukemia is a form of cancer that occurs at the level of the spinal
marrow. Inside the spinal marrow there is a type of immature blood
cells that are called stem cells. These cells have a neutral initial
state and later develop into different types of blood cells (white
blood cells, red blood cells and platelets).
Leukemia interferes in the normal process of cell maturation, leading
to an accumulation of partially developed blood cells in the marrow,
blood and later in body organs. Most of these resulted cells are
inefficient inside the organism, as they can’t carry out the activity
of normal blood cells.
Depending on to the rate of development, the disease can either be
acute leukemia (developing very rapidly), or chronic leukemia (slow
developing).
Particular to acute leukemia is the inability of stem cells (immature
cells that can be found within the bone marrow) to reach the state of
maturity. These immature blood cells tend to continuously divide and
they accumulate in the bloodstream. Acute leukemia develops very
rapidly and people who suffer from it need immediate treatment and
specific therapy. If mistreated or ignored, acute leukemia causes the
death of affected patients within a few months. While certain forms of
acute leukemia are usually successfully treated, other forms don’t
respond well to the specific treatment.
A characteristic of the chronic type of leukemia is that the diseased
cells usually come from more mature cells, but in most cases they
aren’t developed normally. The leukemia cells have long periods of life
and they tend to accumulate within the bloodstream. Although normal
people have between 5000 and 10000 white blood cells in their body,
people who suffer from chronic leukemia may have more than 100000.
Lymphocytic and myelogenous types of leukemia are developed from
different types of cells: the lymphocytic type of leukemia develops
from cells called lymphoblasts or lymphocytes in the spongious tissue
of the bones, while the myelogenous type of leukemia (sometimes refered
to as myeloid and myelocytic leukemia) develops from myeloid cells.
Judging by the types of cells involved in the development of leukemia
and by the rate of cellular division specific to each form of the
disease, the main types of leukemia are: acute myelogenous leukemia
(AML), chronic myelogenous leukemia (CML), acute lymphocytic leukemia
(ALL) and chronic lymphocytic leukemia (CLL).
In addition to the common forms of chronic leukemia, there are also
some rare types. Hairy cell leukemia (HCL), just like chronic
lymphocytic leukemia, has a slow progression. The cells of hairy cell
leukemia are different from other diseased cells mainly through their
aspect. Hairy cell leukemia doesn’t usually respond well to treatment.
Prolymphocytic leukemia is a very rare and unusual form of chronic
lymphocytic leukemia.
Some cancers, called lymphomas, are caused by abnormal blood cells that
are present in the lymph nodes, liver, spleen or other organs. These
particular types of cancer don’t occur at the levels of the bone marrow
and have a development that is not characteristic to most forms of
lymphocytic leukemia.
