Brain, Spine and Skull Base Cancer Program

What is Leukemia?

Leukemia is cancer that starts in the tissue that forms blood cells (called bone marrow). Blood cells develop from stem cells in the bone marrow. These stem cells mature into specialized blood cells.White blood cells help fight infection. There are several types of white blood cells.Red blood cells carry oxygen to tissues throughout the body. Platelets help form blood clots that control bleeding.

Leukemia Blood Cells imageDifferent types of white blood cells develop in the bone marrow. A stem cell matures into either a myeloid stem cell or a lymphoid stem cell.

A myeloid stem cell matures into a myeloid blast. The blast can form a red blood cell, platelets, or one of several types of white blood cells. A lymphoid stem cell matures into a lymphoid blast. The blast can form one of several types of white blood cells, such as B cells or T cells.

Leukemia occurs when the bone marrow makes large numbers of abnormal white blood cells. As the number of abnormal cells increases in the blood and bone marrow, there is less room for healthy cells.

To learn more about leukemia, visit the Leukemia Cancer Types & Topic section.