Blood or bone marrow contains less than 10% blasts.
Marked expansion of morphologically mature red blood cells that show only mild functional abnormalities.
Malignant cells restricted to bone marrow, liver, spleen and peripheral blood.
Symptoms related to:
- Organ involvement (hepatosplenomegaly)
- Hyperviscosity
- Metabolic effects of hyperproliferation
Clinically stable for many years.
Chronic phase pathology:
- Mild normochromic, normocytic anaemia
- Marked leukocytosis
- 3 - 30X peripheral neutrophils
- 10 - 100X total blood granulocyte count
- Thrombocytosis
- Peripheral blood smear shows myeloid cells at all stages of differentiation
- Myeloblasts and promyeloblasts account for <15% of differential count
- Increased basophils and eosinophils
- Bone marrow and spleen may contain lipid-laden histiocytes
- Bone marrow is hypercellular
- Granulocytic hyperplasia
