The correct answer is C: Leukemoid reaction
Comment: A marked increase in total WBC and myeloid elements in the peripheral blood can be found in settings other than leukemia, including infections and post-hemorrhage. Testing for the presence of the Ph chromosome and BCR-ABL gene product help to rule out a diagnosis of CML, as would a more invasive bone marrow examination. Also to be noted on this leukemoid reaction smear is the relatively large number of more mature neutrophils than would be expected in leukemia, which tends to exhibit more immature forms. Click here for the comparative pathology.
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Melo JV, Hughes TP, Apperley JF. Chronic myeloid leukemia. Hematology Am Soc Hematol Educ Program. 2003:132–52. Review. PubMed PMID: 14633780.