laboratory features

Last reviewed 01/2018

  • 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