Subtypes of childhood AML
Childhood acute myelogenous leukemia (AML) has different subtypes. Knowing the subtype of your child’s leukemia helps doctors to treat your child. There are 2 systems used to classify AML into subtypes.
FAB subtypes of AML
The French-American-British (FAB) classification system is most commonly used for childhood AML. It classifies AML based on how the leukemia cells (blasts) look under the microscope. It divides AML into major subtypes based on the type of cell involved and how mature it is. Maturity is described as differentiation, which is the normal process by which immature (unspecialized) cells become mature (specialized) cells.
The FAB subtypes of AML include:
- M0: AML without differentiation
- M1: AML with minimal differentiation
- M2: AML with differentiation
- M3: acute promyelocytic leukemia (APL)
- M3v: APL, microgranular variant
- M4: acute myelomonocytic leukemia (AMML)
- M4Eo: AMML with eosinophilia
- M5: acute monocytic leukemia (AMoL)
- M5a: AMoL without differentiation
- M5b: AMoL with differentiation
- M6: acute erythroid leukemia (AEL)
- M6a: erythroleukemia
- M6b: pure erythroid leukemia
- M6c: presence of myeloblasts and proerythroblasts
- M7: acute megakaryoblastic leukemia (AMKL)
WHO subtypes of AML
The World Health Organization (WHO) classification is a newer system that also considers any genetic changes, such as translocation (rearrangement) of chromosomes.
The WHO subtypes of AML include:
AML with recurrent genetic abnormalities
- AML with t(8;21)(q22;q22); RUNX1-RUNX1T1
- AML with inv(16)(p13.1;q22) or t(16;16)(p13.1;q22); CBFB-MYH11
- APL with t(15;17)(q22;q12); PML-RARA
- AML with t(9;11)(p22;q23); MLLT3-MLL
- AML with t(6;9)(p23;q34); DEK-NUP214
- AML with inv(3)(q21;q26.2) or t(3;3)(q21;q26.2); RPN1-EVI1
- AML (megakaryoblastic) with t(1;22)(p13;q13); RBM15-MKL1
- AML with mutated NPM1
- AML with mutated CEBPA
- AML with BCR-ABL1
AML with myelodysplasia-related changes
Therapy-related myeloid neoplasms (AML related to previous chemotherapy or radiation therapy)
AML, not otherwise specified
- AML with minimal differentiation
- AML without maturation
- AML with maturation
- AMML
- AMoL
- AEL
- pure erythroid leukemia
- erythroleukemia
- AMKL
- acute basophilic leukemia
- acute panmyelosis with myelofibrosis
- myeloid sarcoma
Myeloid proliferations related to Down syndrome
- transient abnormal myelopoiesis
- myeloid leukemia associated with Down syndrome
Mixed phenotype acute leukemia (MPAL)