A 45-year-old woman presents with marked splenomegaly. Her leukocyte count is increased to 300,000/uL. The differential count reveals the presence of small numbers of myeloblasts and promyelocytes, with a predominance of myelocytes, metamyelocytes, bands, and segmented neutrophils. Basophils are also increased in number, as are platelets. The patient is not anemic. Leukocyte alkaline phosphatase is decreased. Which of the following describes a major characteristic of this disorder?
CML is almost invariably marked by the finding of the Philadelphia chromosome, a small residual chromosome 22 with the addition of a small segment of chromosome 9, resulting from a 9;22 translocation.
9;22 translocation
Expansion of mature B lymphocytes within multiple lymph nodes
Hypogammaglobulinemia
Neoplastic cells exhibiting hair-like filamentous projections
Chronic Myelogenous Leukemia