A 55 year old man newly diagnosed with leukemia undergoes genetic studies that reveal a t(9;22) translocation (the Philadelphia chromosome). Which of the following would a complete blood count most likely show?
The Philadelphia chromosome is a hallmark of chronic myeloid leukemia (CML). CML typically presents with markedly increased numbers of circulating neutrophils and metamyelocytes, with lesser numbers of eosinophils and basophils and a small number of blasts. The disease follows an indolent course, and usually progresses to an accelerated phase with increased numbers of circulating blasts only after several years. An increased lymphocyte count would be seen in chronic lymphocytic leukemia (CLL), another indolent leukemia. Increased numbers of blasts are seen in the late stages of CML and CLL, or in the acute leukemias. The Philadelphia chromosome is occasionally associated with acute lymphoblastic leukemia and acute myeloblastic leukemia, but these are diseases of children and young adults. Ref: Wyatt C., Butterwoh IV J.F., Moos P.J., Mackey D.C., Brown T.G. (2008). Chapter 12. Hematopathology. In C. Wyatt, J.F. Butterwoh IV, P.J. Moos, D.C. Mackey, T.G. Brown (Eds), Pathology: The Big Picture.
Increased lymphocyte count
Increased neutrophil count
Numerous lymphoblasts
Numerous myeloblasts