Overview

Leukemia is a cancer of the blood. It begins when normal blood cells change and grow uncontrollably. Acute myeloid leukemia (AML) is a type of leukemia that is a cancer of the blood-forming tissue in the bone marrow. AML may also be called acute nonlymphocytic leukemia or acute myelogenous leukemia.

Bone marrow is the spongy, red tissue in the inner part of the large bones and is the source of a person’s blood. Normal immature blood cells are called blasts. Blasts mature into one of three different types of blood cells:

• White blood cells, which fight infection in the body
• Red blood cells, which carry oxygen and other nutrients throughout the body
• Platelets, which help the blood to clot

In AML, the bone marrow produces large numbers of abnormal cancerous cells, also called blasts or myeloblasts because they look similar to normal immature blast cells. Instead of becoming the three types of normal mature blood cells, the cancerous cells divide rapidly and uncontrollably, are unable to mature and function like normal blast cells, and do not die easily. Eventually, these myeloblasts fill up the bone marrow, preventing normal cells from being produced, and then accumulate in the bloodstream. They can also invade the lymph nodes, brain, skin, liver, kidneys, ovaries (in girls), testicles (in boys), and other organs. AML cells occasionally form a solid mass or tumor, called a chloroma.

Both children and adults can have leukemia. This section is about AML that occurs in children, sometimes called pediatric AML.