​FAB M0
No definitive myeloid differentiation
Primitive leukemic blasts

​AML M1
Predominately poorly differentiated myeloblast

​

​

• ​Adoloscent males

• Clonal blast

• TdT and T cell antigen

• ​Antigen independent

• Stages indicated by stages of TdT, surface markers, and immunoglobulin

• Disease of children

• Neutropenia, anemia, thrombocytopenia, and variable WBC

• Fever, pain, weightloss

• ​Deeply basophilic cytoplasm

• Vacolulated

​Age

​All ages, usually children

​Adults

​Clinical onset

​Sudden

​Insidious

​Course (untreated)

​less than 6 months

​2-6 year

​Leukemic cells

​Immature; many blasts

​Mature

​Anemia

​Mild to severe

​Mild

​Thrombocytopenia

​Mild to severe

​Mild

​WBC

​Variable

​Increased

​Organomegaly

​Mild

​Prominent

​Age

​Common in adults, rare in children

​Common in children, rare in adults

​Blood

​Anemia, neutropenia, thrombocytosis, myeloblast, and promyelocytes

​Anemia, neutropenia, thrombocytosis, lymphoblasts, and prolymphocytes

​Morphology

​Medium to large blasts, more cytoplasm than lymphoblasts, cytoplasmic granules, Auer rods; fine nuclear chromatin and distinct nucleoli

​Small or medium blasts scare cytoplasm, no granules, fine nuclear chromatin,n and indistinct nucleoli

​Cytochemistry

​Positive peroxidase and sudan black B

​Negative peroxidase and sudan black B

​Extramedullary and focal disease

​Common in spleen and liver, less common in lymph nodes and CNS

​Common in lymph nodes, spleen, and liver, CNS, and gonads.

​Blast Nuclei

​Usually larger, finely dispersed chromatin, and variable nucleoli

​Variable size small to medium, fine to more mature chromatin, and may or may not have nucleoli

​Cytoplasm

​Moderately abundant, fine small granules are often present, and may see Auer rods

​Usually scant, coarse granules may be present

​Background marrow

​dysplastic may be present

​dysplastic usually not present

​

• ​

• ​More than 20% of cells are blasts

• More than 50% of cells are in at least two lines (pretreatment specimen)

• Severe pancytopenia

• AML arising in preexisting MDS or MDS/MPN qualifies for diagnoses

• Aberrant antigen expression

• heterogeneous disease

• Loss of chromosome 5q and 7q

​

• ​

• ​Alkylating agent/radiation-deletion or translocation of 5q and 7q, multilineage in peripheral blood or bone marrow, basophilia, and bone marrow showing reticulum fibrosis

• Topoisomerase II inhibitor-translocation of 11q23

• ​FAB M0

• No definitive myeloid
  

• ​AML M1

• Without maturation

• Composed of pre-dominantly poorly differentiated myeloblasts

• ​FAB M2

• Infiltrate more than 20% blasts and evidence of maturation

• More than 10% of cells at different stages of granulocytic maturation

• FAB ​M4

• Neutrophilic and monocytic differentiation

• More than 20% blasts

• More than 20% precursors of neutrophils and monocytes of the bone marrow cellularity

• ​FAB M5a (majority monoblasts) and M5b (promonocytes/monocytes dominance)

• Predomiincaof monocytic lineage cells

• More than 80% of leukemic cells

• ​FAB M6

• abnormal proliferation of immature erythroid precursors

• More than 80% of immature erythroid

• 30% proerythroblasts

• ​FAB M7

• Neoplastic proliferation of megakaryoblasts and atypical megakaryocytes

• More than 20% blast Acute Leukemia

• 50% or more are blasts of megakaryocytic