Understanding the Different Forms of Leukemia

Leukemia is a cancer of the bone marrow. More specifically, leukemia occurs when the cancer starts in the cells in bone marrow which are responsible for making blood.


Once the cell is altered, it doesn’t act or perform properly. Typically, these cancerous cells grow too quickly and can live longer than they should. The cancerous cells continue their growth and push out healthy bone marrow spells. From the bone marrow, leukemia can use the bloodstream to spread to other parts of the body and other organs. 

Leukemia can be confusing because there are many different forms of it. Most leukemia nomenclature comes from which cells in the bone marrow are affected first. The other part of leukemia is how the cells change. 

Chronic vs. Acute Leukemias

Chronic and acute leukemia are the first main classification system. Chronic leukemia is when cells manage to mature somewhat, while acute leukemias occur when the cells are still immature.

In chronic cases, the leukemia cells appear to have matured and grown properly. However, in fact, they have not done that. These white blood cells don’t do the job that they are supposed to do. In addition, chronic cells don’t die quickly. In fact, they will live long beyond the normal lifespan of healthy non cancerous cells. These cells that are extending the life cycle mean that they end up becoming more and more prevalent and build up within the bone marrow. This build up can take a long time. Many people go years without realizing that they have chronic leukemia. 

Acute leukemia instead is due to immature blood cells that don’t reach maturity. This form of leukemia happens far more quickly than chronic forms of leukemia. These immature cells are unable to do a proper job, and don’t produce white or blood red blood cells correctly. These immature cells multiply rapidly and make the condition quickly worsen. Treating acute leukemia means quick and heavy response to try and get it under control before too much damage can be done. 

Main Types of Leukemia

There are four main types of leukemia that people can get. They are: 

  1. Acute Myeloid Leukemia - Referred to as AML, this type of leukemia has immature cell growth that starts in the myeloid cells. These cells create red and white blood cells as well as platelets. 
  2. Chronic Myeloid Leukemia - This leukemia is commonly referred to as CML. It starts in the same cells as the acute version, but instead, the cells mature imperfectly. The cells can look normal, but function poorly. 
  3. Acute Lymphocytic Leukemia - ALL occurs in the cells of the lymphocytic system. These cells will be immature cells. This form of cancer is the most likely leukemia that can occur in children. The good news is that this is often treated well. 
  4. Chronic Lymphocytic Leukemia - CLL also affects the cells of the lymphocytic system and they will mature in an imperfect fashion. 

It’s important to know that lymphocytic leukemia and lymphoma are two seperate things. Lymphomas are very close to lymphocytic leukemia because they start in the same cells. However, people who get lymphomas, have the cancerous cells form outside of the bone marrow. It’s commonly affecting the lymph nodes and tissues throughout the body rather than going from the bone marrow out.