Subtypes

AML blasts are classified based on how much they look like normal, immature bone marrow blast cells and, more recently, on cytogenetics. In the recent past, AML was divided into eight major subtypes according to a system called the FAB classification scheme (using levels M0 to M7). More recently, a new method of subtyping AML is used that takes into consideration the cytogenetic causes of AML. This is called the WHO (World Health Organization) classification. These subtypes include:

• Acute myeloid leukemia with recurrent genetic abnormalities
  • Acute myeloid leukemia with t(8;21)(q22;q22), AML1/ETO)
    
    
  • Acute myeloid leukemia with abnormal bone marrow eosinophils and inv(16)(p13q22) or t(16;16)(p13;q22), (CBFß/MYH11)
    
    
  • Acute promyelocytic leukemia with t(15;17)(q22;q12), (PML/RARa) and variants
    
    
  • Acute myeloid leukemia with 11q23 (MLL) abnormalities
  
  
• Acute myeloid leukemia with multilineage dysplasia
  • Following MDS or MDS/MPD
    
    
  • Without antecedent MDS or MDS/MPD, but with dysplasia in at least 50% of cells in two or more myeloid lineages
  
  
• Acute myeloid leukemia and myelodysplastic syndromes, therapy related
  • Alkylating agent/radiation-related type
    
    
  • Topoisomerase II inhibitor-related type (some may be lymphoid)
    
    
  • Others
  
  
• Acute myeloid leukemia, not otherwise categorized
  • Classify as:
    • Acute myeloid leukemia, minimally differentiated (previously called M0)
      
      
    • Acute myeloid leukemia without maturation (previously called M1)
      
      
    • Acute myeloid leukemia with maturation (previously called M2)
      
      
    • Acute myelomonocytic leukemia (previously called M4)
      
      
    • Acute monoblastic/acute monocytic leukemia (previously called M5)
      
      
    • Acute erythroid leukemia (erythroid/myeloid and pure erythroleukemia) (previously called M6)
      
      
    • Acute megakaryoblastic leukemia (previously called M7)
      
      
    • Acute basophilic leukemia
      
      
    • Acute panmyelosis with myelofibrosis
      
      
    • Myeloid sarcoma