FAB and WHO Classifications for Acute Myeloid Leukemia
Two staging systems are commonly used for acute myeloid leukemia (AML). The French-American-British (FAB) classification system is based on morphology to define specific immunotypes. The World Health Organization (WHO) classification reviews chromosome translocations and evidence of dysplasia. [1]
Table. FAB classification of AML (Open Table in a new window)
FAB subtype |
Name |
Adult AML patients (%) |
M0 |
Undifferentiated acute myeloblastic leukemia |
5% |
M1 |
Acute myeloblastic leukemia with minimal maturation |
15% |
M2 |
Acute myeloblastic leukemia with maturation |
25% |
M3 |
Acute promyelocytic leukemia |
10% |
M4 |
Acute myelomonocytic leukemia |
20% |
M4eos |
Acute myelomonocytic leukemia with eosinophilia |
5% |
M5 |
Acute monocytic leukemia |
10% |
M6 |
Acute erythroid leukemia |
5% |
M7 |
Acute megakaryocytic leukemia |
5% |
WHO classification of AML and related neoplasms
AML with recurrent genetic abnormalities [2, 3] :
-
AML with t(8;21)(q22;q22); RUNX1-RUNX1T1
-
AML with inv(16)(p13.1q22) or t(16;16)(p13.1;q22); CBEB-MYH11
-
Acute promyelocytic leukemia (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)(q21q26.2) or t(3;3)(q21;q26.2); RPN1-EVI1
-
AML (megakaryoblastic) with t(1;22)(p13;q13); RBM15-MKL1
-
Provisional entity: AML with mutated NPM1
-
Provisional entity: AML with mutated CEBPA
AML with myelodysplasia-related change
Therapy-related myeloid neoplasms
AML, not otherwise specified:
-
Undifferentiated AML (M0)
-
AML with minimal differentiation (M1)
-
AML without maturation (M2)
-
AML with maturation (M2)
-
Acute myelomonocytic leukemia (M3)
-
Acute monoblastic/monocytic leukemia (M4)
-
Acute erythroid leukemia (M5)
-
Pure erythroid leukemia (M6)
-
Erythroleukemia, erythroid/myeloid (M6)
-
Acute megakaryoblastic leukemia (M7)
-
Acute basophilic leukemia
-
Acute panmyelosis with myelofibrosis
Myeloid sarcoma
Myeloid proliferations related to Down syndrome:
-
Transient abnormal myelopoiesis
-
Myeloid leukemia associated with Down syndrome
Blastic plasmacytoid dendritic cell neoplasm