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Acute Lymphocytic Leukemia (ALL): Introduction 

What is cancer?


What is leukemia?

Leukemia is different from most other types of cancer. Leukemia is cancer that starts in the bone marrow, which is where new blood cells are made. Leukemia cells are early forms of blood cells, most often white blood cells. When a person has leukemia, the body makes too many abnormal blood cells. Leukemia cells do not usually form tumors, but they can travel with the blood all over the body. That means CLL can affect organs all over the body.               

Two types of white blood cells can turn into leukemia: 

  • Lymphoid cells (lymphocytes). This is called lymphocytic leukemia.



What is acute lymphocytic leukemia (ALL)?

Acute lymphocytic leukemia (ALL) is a type of leukemia that starts in very early forms of lymphocytes. These are called lymphoblasts, or just blasts. The condition is also known as acute lymphoblastic leukemia. As the blasts grow, they can crowd out the normal cells in the bone marrow. This can lead to not enough of different types of blood cells. People with ALL have too many lymphocytes in their blood, but these cells are not normal and don't help fight infection. In fact, people with ALL are more likely to get infection. They can also have not enough red blood cells (anemia), which can cause fatigue. And they can have not enough platelets, which can lead to excess bleeding or bruising. 


Subtypes of ALL

ALL also comes in different subtypes. These are based on what type of lymphocytes the leukemia starts in, and how mature the cells are. Which subtype of ALL you have can affect both your treatment and prognosis (outlook). Ask your doctor about your subtype of ALL and what it means in your case. The subtypes include:

B-cell ALL


  • Early Pre-B ALL (pro-B ALL)

  • Common ALL

  • Pre-B ALL

  • Mature B-cell ALL (also known as Burkett leukemia)

T-cell ALL


  • Pre-T ALL

  • Mature T-cell ALL

Talk with your healthcare provider


Online Medical Reviewer: Alteri, Rick, MD
Online Medical Reviewer: Gersten, Todd, MD
Date Last Reviewed: 9/23/2015
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