What is A.L.L.?

Acute Lymphoblastic Leukemia - ALL

Acute lymphoblastic leukemia (ALL) is a fast-growing cancer of a type of white blood cells called lymphocytes. These cells are found in the bone marrow and other parts of the body. ALL occurs when the body produces a large number of immature lymphocytes. The cancer cells grow quickly and replace normal cells in the bone marrow. Bone marrow is the soft tissue in the center of bones that helps form all blood cells. ALL prevents healthy blood cells from being made. Life-threatening symptoms can occur.

Normally, lymphocytes have a set lifespan. They grow, multiply and die in a controlled manner after which they are replaced by a new cell. In ALL, a single lymphocyte cell in the bone marrow is mutated or changed allowing it to grow and divide in a rapid and uncontrolled manner. The resulting 'abnormal' cells are usually 'immature' and known as (lympho-) blast cells which is why the condition is called acute lymphoblastic leukaemia.

These abnormal cells fill the bone marrow and eventually affect its ability to produce all types of red and white blood cells causing:

• An increased risk of infection due to a reduced number of functioning white blood cells

• Anemia and fatigue due to a reduced number of red blood cells

• Bleeding and bruising due to a reduced number of platelets

The progression of ALL (Figure 2, below) can be very rapid (known as 'acute'). Mutated cells can spread into different tissues including the fluid in the spine (cerebrospinal fluid) which is the reason early diagnosis and treatment is so important.

Figure 2: The progression of ALL. Normally the bone marrow produces a combination of white blood cells (to fight infection), red blood cells (to carry oxygen) and platelets (to stop bleeding). A single abnormal ALL cell can multiply and fill the bone marrow, reducing its capacity to produce normal blood cells. Reduced numbers of white blood cells make you more susceptible to infection while reduced production of red blood cells (known as anaemia) will make you feel fatigued, and reduced platelets will make you more prone to bleeding and bruising. In later stages of the disease, the abnormal ALL cells can spread to other organs such as the liver or central nervous system. Your doctor will know all of this and select the most appropriate treatment to destroy all of the ALL cells in your body.

Want to learn more about Acute Lympoblastic Leukemia? 
Here are some good sites:

NIH

Webmd