What is childhood leukemia?
Leukemia is a cancer that originates in the blood stem cells. Stem cells are basic cells, or mother cells, capable of transforming into different cell types that have distinct functions.
Blood stem cells can become either lymphoid stem cells or myeloid stem cells.
Lymphoid stem cells are transformed into lymphocytes, a type of white blood cells. Lymphocytes produce antibodies that help fight infections.
Myeloid stem cells produce red blood cells, granulocytes, monocytes, or platelets. Red blood cells transport oxygen to all tissues of the body. Granulocytes and monocytes are types of white blood cells that destroy bacteria and fight infections. Platelets form clots in damaged blood vessels to stop bleeding.
Leukemia occurs when blood stem cells present in the bone marrow undergo changes that make their mode of growth or abnormal behaviour. These abnormal cells, called leukemic cells, gradually multiply and eventually invade normal blood cells which are then unable to perform their tasks.
There are many different types of leukemias that are first categorized according to the kind of blood stem cell from which they develop. Lymphoid leukemia (usually called lymphoblastic leukemia in adults) originates in abnormal lymphoid stem cells. Myeloid leukemia (also known as myeloid leukemia) begins in abnormal myeloid stem cells.
The types of leukemia are then subdivided according to the speed at which the disease develops and evolves. Acute leukemia starts suddenly and develops in a few days or weeks. Chronic leukemia develops slowly over the course of months or even years.
Acute lymphoblastic leukemia (LAL) is the most commonly diagnosed type of leukemia in young children and affects boys more than girls. Acute myeloid leukemia (LAM) is less common and usually occurs more frequently in girls than in boys.
Rare types of leukemia in children may also appear. Examples include chronic lymphoid leukemia (LLC) and chronic myeloid leukemia (CML).
0 comments:
Post a Comment