ABSTRACT
Purpose:To report three cases of myelodysplastic syndrome(MDS) transformed to atypical chronic myeloid leukemia(aCML).Methods:Compared the clinical findings,hemograms and bone marrow features in two different courses of the disease,discussed with review of related literatures.Results:The three patients were all old age.They onset with chronic anemia,the results of BM smear were MDS-RAS and MDS-RAEB;Then leukocytosis occurred in 6-65 months.The aCML were diagnosed according to the BM smear and normal chromosome.Conclusions:The MDS/MPD is a new category of the WHO classification that have both dysplastic and proliferative features.Atypical CML lacks the Ph chromosome and BCR/ABL fusion gene that are the hallmarks of classic CML.This kind of case is seldom seen.