NCCN Guidelines for Patients
Acute Lymphoblastic Leukemia, Version 1.2017
Acute lymphoblastic leukemia
Most blood cells are made in the bone marrow. Bone
marrow is the soft, sponge-like tissue in the center of
See Figure 1
. Blood cells are made
from special blood-forming cells called blood stem
cells. Blood stem cells can become any type of
mature blood cell.
Blood stem cells go through a series of changes as
they grow and develop to make new blood cells.
See Figure 2.
Blast cells are new, very young
(immature) blood cells that grow into adult (mature)
blood cells over time. Different types of blast cells
become different types of mature blood cells. Once
they are mature, the blood cells leave the bone
marrow and enter the bloodstream.
Leukemias are cancers that start in blood-forming
cells in the bone marrow. There is more than one
type of leukemia. Each type of leukemia is named
based on how fast it grows and the type of blood cell
in which it begins.
This book focuses on ALL (
eukemia). “Acute” means the leukemia grows and
progresses very fast. “Lymphoblastic” means it starts
in young white blood cells called lymphoblasts.
Lymphoblastic lymphoma is similar to ALL. The main
difference is that it starts in lymphoblasts within the
Blood stem cells make all
types of blood cells
A blood stem cell goes through
many steps to become a red
blood cell, white blood cell, or
platelet. Blast cells are very
young blood cells that grow
into mature blood cells over
time. Lymphoblasts grow into
mature white blood cells called
lymphocytes. White blood cells
help protect the body from
infection and disease.
Myeloid stem cell
Blood stem cell
Lymphoid stem cell
Illustration Copyright © 2017 National Comprehensive Cancer Network