
Morphology
Chronic Phase (CP)
- The most common findings are a normocytic anaemia and a leucocytosis, mainly of neutrophil granulocytes with a left shift, but also an increase in eosinophils and basophils.
- Initial films need to be looked at carefully since basophils may be poorly granular. An accurate basophil count is required for some of the prognostic systems.
- The platelet count is often raised, and occasionally may be the main (or only) abnormal peripheral blood finding.
- The bone marrow shows an intense hyperplasia involving the granulocyte and megakaryocytic lineages. Cytogenetics and DNA analysis are required to establish the diagnosis.
Accelerated Phase (AP)
The 2016 WHO criteria2 for the diagnosis of the accelerated phase of CML includes response to TKI therapy, see table 2, page 3.
Blast Phase (BP)
Defined by ≥20% blasts in peripheral blood or bone marrow or proliferation of extramedullary blasts.
The majority of BPs are of myeloid lineage, but 20-30% of cases are lymphoblaststic (usually B-cell). Sequential lymphoid then myeloid blasts crisis have been reported.
80% of patients in BP show clonal evolution.
Topic Code: 6215