[Differential diagnosis of chronic myeloid leukemia and the related disorders]

Chronic myeloid leukemia(CML) is a generic term that includes five subtypes; i.e. chronic granulocytic leukemia(CGL) (95% of all CML, 90% are Ph+, 5% are Ph-, BCR/ABL+), atypical CML(survival is worse than that of CGL), chronic myelomonocytic leukemia(a subtype of myelodysplastic syndrome), chronic neutrophilic leukemia (Ph-, BCR/ABL-) and juvenile CML(Ph-, BCR/ABL-). It is not so easy to make a diagnosis of Ph-negative CML. Also, about 25% of adult acute lymphoid leukemia(ALL) patients and some essential thrombocythemia patients have Ph chromosome. In addition, about a half of cases with Ph-positive ALL have the same size of BCR/ABL fusion protein as that in Ph-positive CML. It is necessary to distinguish them by the distinctive morphological, cytogenetical and immunological characteristics of these diseases.