Peripheral blood smear results vary depending on the phase of disease progression.
In CP, the peripheral blood shows leukocytosis ranging from slightly above normal (greater than 12.0 × 103/mcL) to extremely high (over 100.0 × 103/mcL).
The peripheral blood smear shows a predominance of neutrophil proliferation in different stages of maturation, with the majority of neutrophilic cells in the mature neutrophil, band neutrophil, and myelocyte stages. The granulocytes are relatively normal morphologically, with minimal dysplastic features and no toxic changes. The percentage of eosinophils and basophils may be increased, especially as the disease progresses. Blast cells usually account for less than 10% of the WBC count. The platelet count ranges from normal to greater than 1 million/mcL. A normocytic, normochromic anemia is typically present.
In BP, the peripheral blood smear may present as an acute leukemia, showing more than 20% blasts. The granulocytes may show marked dysplasia in both immature and mature stages. An increased amount of eosinophils and basophils is common. In BP, thrombocytopenia is more common than thrombocytosis.
