Inside the large bones of the human body is a spongy tissue called bone
marrow. Bone marrow makes cells called “blasts” that develop into several types
of blood cells, each with a specific function.
The lymph system is made of thin tubes that branch into all parts of the
body. Groups of lymph nodes (small bean shaped organs) are found along the
routes. Lymph is a colorless, watery fluid containing lymphocytes that are
carried by lymph vessels along the network of the system.
Most people are familiar with the fact that the underarm stores clusters of
lymph nodes, but the neck, pelvis, abdomen, spleen, and a few other organs are
also parts of the lymph systems. The spleen makes lymphocytes and filters old
cells from the blood.
Lymphocytes make substances called antibodies, which fight off infection by
attacking and digesting harmful bacteria in the body. In acute leukemias, the
developing lymphocytes do not mature. They collect in the lymph tissues,
causing them to sell. They make their way through the marrow and blood,
crowding out the other healthy cells.
Bone marrow creates red blood cells, white blood cells, and platelets. Red
blood cells carry oxygen and other materials to all body tissues, white blood
cells fight infection, and platelets cause blood to clot.
If the marrow cannot produce enough red blood cells, the patient will become
anemic. If the marrow cannot produce enough healthy white blood cells, the
patient’s immune system becomes compromised and any minor infection can become
deadly. If the marrow cannot produce enough platelets for blood to clot
normally, cuts will bleed profusely and the patient will easily bruise. The
cancerous lymphocytes can also invade the brain, the spinal cord, and other
critical organs.
The final division into seven types of leukemia looks like this:
1) Adult Acute Lymphocytic Leukemia (Adult ALL): Too many abnormal
(immature) infection-fighting lymphocytes are found in the bone marrow and
blood. Often causes a shortage of platelets as well.
2) Childhood Acute Lymphocytic Leukemia (Childhood ALL): Same definition as
Adult ALL. This type accounts for 85% of leukemia cases in children and is the
most common type of childhood cancer. It is also the easiest to treat and has a
high success rate of cures.
3) Adult Acute Myeloid Leukemia (Adult AML): Also called Acute
Non-lymphocytic Leukemia (ANLL). Granulocytes do not mature and become too
numerous.
4) Childhood Acute Myeloid Leukemia (Childhood AML): Same definition as the
adult type.
5) Chronic Lymphocytic Leukemia (CLL): The developing white cells do not
mature correctly and too many are made. This is the most common leukemia and is
usually found in people sixty years of age or older.
6) Chronic Myelogenous Leukemia (CML): This disease is also called Chronic
Granulocytic Leukemia. As with the AML, the granulocytes do not mature and live
longer than a normal cell. In most CML patients, the genetic material of the
leukemia cells has an abnormal chromosome that doesn’t go away, even after
treatment is completed. It is called a Philadelphia
chromosome.
7) Hairy-Cell Leukemia (HCL): With HCL, malignant cells are found in the
bone marrow and blood. HCL is uncommon and characterized by an enlarged spleen
without enlarged lymph nodes. HCL causes low numbers of all blood cell types.
The strange sounding (in comparison to the others) name of this leukemia
comes from the appearance of the cells. Beneath the microscope, the cancerous
cells look as though hair is growing around their edges.