Laboratory features

• peripheral blood:
  • the white count is raised, usually > 30 x 10^9 / litre, commonly, 100-250 x 10^9 / litre
  • differential:
    • the myeloid series is left-shifted with mature forms dominating
    • granulocytes especially neutrophils and myelocytes, greatly increased
    • basophilia and eosinophilia is common (1)
    • low percentage of blasts
  • red cells - anaemia in later stages, normocytic, normochromic
• platelets - often normal, may be increased or decreased
  
  
• bone marrow:
  • hypercellular with prominent granulocytic hyperplasia
  • megakaryocytic numbers often raised
  • high proportion of blasts suggests transformation
    
    
• trephine biopsy - useful to assess degree of fibrosis and loss of marrow fat spaces
  
  
• Philadelphia chromosome - often detected in peripheral blood or bone marrow
  
  
• neutrophil alkaline phosphatase score is low providing evidence of qualitative abnormalities in neutrophils
  
  
• serum vitamin B12 is high due to increased secretion of transcobalamin III
  
  
• serum uric acid and alkaline phosphatase - often raised

Reference:

1. Smith G, Apperley J, Milojkovic D, et al. A British Society for Haematology guideline on the diagnosis and management of chronic myeloid leukaemia. Br J Haematol. 2020 Oct;191(2):17c