What is Acute Lymphoblastic Leukemia (ALL)?

Leukemia is a type of cancer that forms in your bone marrow, the soft, spongy tissue inside your bones where blood cells are produced. Your bone marrow contains immature, blood-forming stem cells that eventually develop into mature red blood cells, white blood cells, and platelets. In Acute Lymphoblastic Leukemia (ALL), the bone marrow produces too many malignant, immature white blood cells called blasts. ALL is "acute" because it is aggressive and progresses quickly. "Lymphocytic" refers to the type of white blood cell (lymphoblasts) that give origin to ALL. These abnormal, immature lymphoblasts do not fight infection and can crowd out your healthy blood cells, causing conditions like anemia (low red blood cells), leukopenia (low white blood cells), and thrombocytopenia (low platelets). White blood cells (WBC) are divided into different sub-types among them neutriohils and lymphocytes. WBC constitute our immune system that fights bacterial, viral, and fungal infections. In AML, the myeloblasts can build up in the body and prevent the WBC from growing and maturing properly. These abnormal, immature WBC cannot fight infection as well as healthy WBC.

ALL is the third most common form of leukemia in the United States, with about 6,000 new cases each year. It is the most common childhood cancer, with about 4,000 of these cases occurring in children. Leukemias and lymphomas, cancers of lymph nodes, are closely related, and the differences can be confusing. Lymphomas start in your lymph nodes and lymphatic tissue. The main difference between lymphoblastic leukemias and lymphomas is that lymphoblastic leukemias almost always involve your bone marrow; whereas, lymphomas start in lymphoblasts in your lymph nodes or other organs and may or may not involve your bone marrow. If your doctor finds cancerous lymphoblasts in your bone marrow and lymph nodes, he or she will have to run additional tests to distinguish between ALL and lymphoma. In ALL, more than 20% of your bone marrow will consist of cancerous lymphoblasts. In lymphomas, the lymph nodes are almost always swollen.