Philadelphia chromosome-positive myelodysplastic syndrome: Is it a distinct entity?

摘要

Clonal cytogenetic abnormalities occur in 50% of de novo myelodysplastic syndrome (MDS) cases and are of prognostic importance [1]. The Philadelphia (Ph) chromosome is classically associated with chronic myeloid leukemia (CML) and is the disease-defining clonal abnormality. In the current WHO classification system of myeloid neoplasms [1] the presence of the Ph chromosome excludes a myeloid neoplasm from any category of myeloproliferative neoplasm (MPN) or MPN/MDS, other than CML. A very rare cytogenetic abnormality reported to occur in MDS is the Ph chromosome, t9;22. In most of the cases reported worldwide so far, the Ph chromosome was found in cases of MDS at the time of progression to acute leukemia.