0521779407-C02 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:53
Chronic Myelogenous Leukemia 337■hepatomegaly, usually mild, in approx. 50%
■pallor, petechiae, ecchymosis, lymphadenopathy less common
tests
Peripheral Blood
■WBC elevated, typically >25,OOO; rarely, WBC is normal
■Differential - blasts (<10% of total WBC) through mature neutrophils
■Absolute basophilia±esosinophilia; monocytes decreased
■Thrombocytosis in 30–50%
■Normochromic, normocytic anemia common
■Low, or absent, leukocyte alkaline phosphatase (LAP)Bone Marrow
■Markedly hypercellular with diminished fat; M:E ratio increased,
often dramatically
■Megakaryocytes typically increased, clustered, small, with dysplas-
tic nuclei; dysplasia in other lineages not usual Blasts and promye-
locytes <10% of total nucleated cellsSpecific Diagnostic Tests
■Cytogenetics: gt;95%+for Philadelphia (Ph) chromosome created
by reciprocal translocation between chromosomes 9 and 22. Adds
a3′segment of the ABL gene (chromosome 9q34) to 5′portion of
BCR gene (chromosome 22q11) creating BCR-ABL oncogene with
intrinsic tyrosine kinase activity lit (9;22)-(q34;ql1).
■Molecular Diagnosis: RT-PCR (reverse transcription-polymerase
chain reaction) for BCR-ABL mRNAdifferential diagnosis
■Leukemoid reactions secondary to sepsis, metastatic carcinoma,
chronic inflammatory disorders may occasionally be confused with
CML. In these instances, LAP score is high, not low; cytogenetics are
normal, molecular tests for bcr-abl are negative
■Other myeloproliferative disorders or myelofibrosis may occasion-
ally present with CML like picture. Cytogenetics and RT-PCR can rule
in or rule out CML.
management
General Measures
■Lower WBC to alleviate symptoms – Hydroxyurea – 0.5 to 6.0 grams/
day