Acute lymphocytic leukemia (ALL) and acute myelogenous leukemia (AML). 1 Acute lymphoblastic leukemia (ALL), also called acute lymphocytic leukemia. 
2 Acute myelogenous leukemia (AML).
3 Hybrid or mixed lineage leukemia.
4 Chronic myelogenous leukemia (CML).
5 Chronic lymphocytic leukemia (CLL).
6 Juvenile myelomonocytic leukemia (JMML).
The major types of leukemia are: 1  Acute lymphocytic leukemia (ALL). 2  This is the most common type of leukemia in young children. 3  ALL can also occur in adults. 4  Acute myelogenous leukemia (AML). 5  AML is a common type of leukemia. 6  It occurs in children and adults. 7  AML is the most common type of acute leukemia in adults. 1 AML is a common type of leukemia. 2  It occurs in children and adults. 3  AML is the most common type of acute leukemia in adults. 4  Chronic lymphocytic leukemia (CLL). 5  With CLL, the most common chronic adult leukemia, you may feel well for years without needing treatment. Leukemia. Leukemias, which are cancers of the bone marrow and blood, are the most common childhood cancers. They account for about 30% of all cancers in children. The most common types in children are acute lymphocytic leukemia (ALL) and acute myelogenous leukemia (AML). Brain and central nervous system tumors. Brain and central nervous system tumors are the second most common cancers in children, making up about 26% of childhood cancers. There are many types of brain tumors, and the treatment and outlook for each is different. There are different types of leukemia. According to the American Cancer Society, acute lymphocytic leukemia (ALL) is the type of leukemia that most commonly affects children, most often between the ages of 2 and 4 years. Acute myelogenous leukemia (AML) is the second most common form of leukemia in children. Chronic myelogenous leukemia (CML) is uncommon in children. Chronic myelogenous leukemia is cancer of the blood in which too many granulocytes, a type of white blood cell, are produced in the marrow. The granulocytes normally fight infection. Key Points. 1  Childhood acute lymphoblastic leukemia (ALL) is a type of cancer in which the bone marrow makes too many immature lymphocytes (a type of white blood cell). 2  Leukemia may affect red blood cells, white blood cells, and platelets. 1 Childhood acute lymphoblastic leukemia (ALL) is a type of cancer in which the bone marrow makes too many immature lymphocytes (a type of white blood cell). Childhood acute lymphoblastic leukemia (also called ALL or acute lymphocytic leukemia) is a cancer of the blood and bone marrow Types of childhood leukemia include: 1  Acute lymphoblastic leukemia (ALL), also called acute lymphocytic leukemia. 2  Acute myelogenous leukemia (AML). 3  Hybrid or mixed lineage leukemia. 4  Chronic myelogenous leukemia (CML). 5  Chronic lymphocytic leukemia (CLL). 6  Juvenile myelomonocytic leukemia (JMML). A tiny number are chronic and develop slowly. Types of childhood leukemia include: 1  Acute lymphoblastic leukemia (ALL), also called acute lymphocytic leukemia. 2  ALL accounts for three out of every four cases of childhood leukemia. 3  Acute myelogenous leukemia (AML). 4  AML is the next most common type of childhood leukemia. Childhood leukemia is a type of leukemia, usually acute lymphocytic leukemia (ALL), and a type of childhood cancer. The cure rate of childhood leukemia is generally higher than adult leukemia, approaching 90%, although some side effects of treatment last into adulthood.  The most common type of leukemia in children is acute lymphocytic (or lymphoblastic) leukemia or ALL, which is further characterized as pre-B, B, or T-cell ALL. Childhood acute myeloid leukemia or AML is less common. About 5% of childhood leukemias are distinct types of chronic myeloid leukemias. Juvenile myelomonocytic leukemia (JMML, NCI PDQ) occurs primarily in children aged 2 or under. Acute promyelocytic leukemia (APL, NCI PDQ) is a distinct subtype of AML. Leukemias. Leukemia is the most-common type of childhood cancer, accounting for approximately 25 percent of all childhood cancers. Leukemia and other diseases of the blood and bone marrow may affect red blood cells, white blood cells, and platelets. 
http://www.mayoclinic.org/diseases-conditions/leukemia/basics/causes/CON-20024914 http://www.cancer.org/cancer/cancerinchildren/detailedguide/cancer-in-children-types-of-childhood-cancers http://www.stanfordchildrens.org/en/topic/default?id=leukemia-90-P02324 http://www.cancer.gov/types/leukemia/patient/child-all-treatment-pdq http://www.webmd.com/cancer/lymphoma/childhood-leukemia-symptoms-treatments https://en.wikipedia.org/wiki/Childhood_Leukemia http://www.ped-onc.org/diseases/leuk.html http://www.childrenscancer.org/main/types_of_childhood_cancer/
different types of childhood leukemia