Chronic Myelogenous Leukemia

Diagnosis

Diagnosing chronic myelogenous leukemia (CML) begins with a medical history review and a physical exam by a blood disorders specialist (hematologist). Your doctor also may request one or more of the tests described below. At Mayo Clinic, all of your diagnostic testing can be completed in a few days rather than in several weeks.

CBC and biopsy

• Complete blood count. The complete blood count (CBC) measures the number of white blood cells, red blood cells and platelets in a blood sample.
• Bone marrow biopsy. A bone marrow sample of your hipbone is taken for examination by a specialist in assessing body tissue (pathologist) to determine the type and extent of leukemia. Mayo Clinic pathologists are internationally known for their diagnostic skill.

Genetic tests

Your doctor may recommend genetic testing on your bone marrow and sometimes your blood to look for the presence of certain unique regions of DNA strands, called genes or chromosomes, that people with CML typically have. These tests include:

• Cytogenetic analysis. Based on the analysis of cells from a blood or bone marrow sample, this test identifies whether you have the Philadelphia chromosome — an abnormal chromosome that is common in people with CML.
• Fluorescence in situ hybridization (FISH). This blood and bone marrow test uses fluorescent probes to identify the fusion of two abnormal genes (BCR-ABL) that are found in the chromosomes of some people with CML.
• Polymerase chain reaction (PCR). Based on DNA, this test identifies the presence of the BCR-ABL gene.