Which type of leukemia is characterized by increased basophils and/or eosinophils in its early stages?

Chronic myelogenous leukemia (CML) is characterized by the proliferation of myeloid cells, including the early presence of basophils and eosinophils. In CML, it is common to see a marked increase in basophils, especially in the chronic phase, and eosinophilia can also be present due to the dysregulation of myeloid lineages. This is significant because the elevated basophils can be a key distinguishing factor in the diagnosis of CML, setting it apart from other types of leukemia.

In the context of other types of leukemia mentioned, while acute myelogenous leukemia and acute lymphocytic leukemia show various types of cells in their presentations, they are typically not characterized by an increase in basophils and eosinophils in the early stages. Acute myelomonocytic leukemia also does not feature this specific increase in basophils and eosinophils at its onset. Therefore, the unique presentation of these cell types in the early stages is a hallmark of chronic myelogenous leukemia.