CHRONIC MYELOGENOUS LEUKEMIA (CML) – BLAST PHASE

Chronic Granulocytic Leukemia (Blast Accelerated Phase); Chronic Myeloid Leukemia (Blast /Accelerated Phase); CML (Blast/Accelerated Phase)

Chronic Myelogenous Leukemia (CML) is a clonal disorder involving the abnormal fusion of chromosomes 9 and 22, forming the Philadelphia chromosome. This in turn produces and abnormal enzyme, tyrosine kinase, which causes abnormal production of white blood cells.

The disease is classified by phase: chronic, accelerated, and blast phases. The accelerated and blast phases of CML refer to those phases of the disease when increased immature white blood cells (blasts) are made and do not mature. When this happens, the disease behaves similarly to acute leukemia. Technically, the chronic phase with occurs <10% blasts in the bone marrow or blood; the accelerated phase occurs with 11-19% blasts in the bone marrow or blood; and the blast phase occurs with 20% or more blasts in the bone marrow or blood.

Symptoms include: fever, night sweats, bone pain, and weight loss. When tiredness, fever, and an enlarged spleen occur during the blast phase, it is called a blast crisis.

Diagnostic testing: CML is diagnosed with tests and procedures such as:

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  Complete blood count (CBC);

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  Bone marrow aspiration and biopsy;

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  Cytogenic analysis of the blood and/or bone marrow; and

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  Reports that address the Philadelphia chromosome and molecular assay of the blood or bone marrow looking for BCR-ABL gene.

Clinical findings: Individuals with CML present with:

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  Splenomegaly (enlarged spleen);

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  Elevated white blood counts exceeding 300,000- 600,000 cells/μL; and

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  Retinas showings papilledema, venous obstruction, and hemorrhages.

ICD-9: 205.10

ICD-10: C92.1

Blast phase is the final phase in the evolution of CML. It behaves like acute leukemia with rapid progression and short survival.

Treatment of CML has improved with the use of tyrosine kinase inhibitors, which block the action of this molecule and its effects on white blood cell production. Standard chemotherapy agents are used along with immunotherapy (interferon) and bone marrow transplantation.

Suggested MER for Evaluation:

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  Results of a CBC exam and bone marrow examinations; and

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  If necessary, cytogenetic (chromosome) studies and molecular analyses can provide additional confirmative information.

Suggested Listings for Evaluation:

REMARKS

CML – Blast Phase currently meets the criteria in 13.06 B 1.