Which of the following is NOT a common finding in chronic myelogenous leukemia?

In chronic myelogenous leukemia (CML), the hallmark features are typically characterized by the presence of a high white blood cell (WBC) count, particularly with an increase in myeloid lineage cells, and often thrombocytosis, which is an elevated platelet count.

Pancytopenia, which refers to a reduction in red blood cells, white blood cells, and platelets, is generally not a common finding in CML. Instead, patients usually present with leukocytosis due to the proliferation of myeloid cells. This abundance of myeloid cells may lead to other complications, but the initial presentation does not typically involve a decrease in all blood cell lines.

Hypercellularity of the bone marrow is a characteristic finding in CML as the marrow is often overpopulated with myeloid precursors. Increased eosinophil count can also occur due to the disease's influence on hematopoiesis, but it is less characteristic than the other options. Thus, the presence of pancytopenia is contrary to the expected findings in CML, making it the correct choice as the one that is not a common feature of the disease.