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Pathology
Peripheral blood findings at diagnosis: median (range)
WBC: 174,000/mm3 (15–850/mm3)
Hemoglobin: 10.3 g/dL (4.9–16.6 g/dL)
Platelet count: 430,000/mm3 (17–3182/mm3)
Left-shifted white cell differential, basophilia, and eosinophilia
Blasts: <15%—chronic phase
Bone marrow findings at diagnosis
Increased cellularity
Increased myeloid-to-erythroid ratio with full myeloid maturation
Blasts <15%—chronic phase
Basophilia
Megakaryocyte hyperplasia
Reticulin fibrosis
Cytogenetics and molecular diagnostics
Philadelphia (Ph) chromosome including variant translocations (90%)
BCR-ABL translocation by FISH (95%)✫
BCR-ABL transcripts by RT-PCR (95%)✫
Chromosomal abnormalities in addition to the Ph chromosome (clonal evolution)†:
(Associated with disease progression, usually absent in the chronic phase at diagnosis)
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Work-up
History and physical examination
CBC and leukocyte differential counts, platelets, electrolytes, liver function tests
HLA typing for patients who are candidates for allogeneic hematopoietic cell transplantation
Bone marrow aspirate and biopsy (bone marrow cytogenetics can detect chromosomal abnormalities other than Ph chromosome that are not detectable using peripheral blood)
BCR-ABL1 transcript levels by quantitative reverse transcriptase polymerase reaction (QPCR) before initiation of treatment.
If collection of bone marrow is not feasible, fluorescence in situ hybridization (FISH) on a peripheral blood specimen with dual probes for BCR and ABL1 genes
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Classification of Disease: Phases of Disease