[Two cases of therapy-related myelodysplastic syndrome].

: Myelodysplastic syndrome (MDS) was sorted out two types; primary type and secondary type caused by irradiation or several drugs. Clinical features and chromosomal analysis were investigated in two patients with secondary MDS, caused by cyclophosphamide (CPM) or rifampicin (RFP) respectively, and fourteen cases of primary MDS hospitalized from 1988 to 1993. Two cases of secondary MDS progressed refractory anemia with excess of blasts (RAEB), however two of 14 patients with primary MDS progressed to acute leukemia. Median survival was similar in two groups. In cytogenitic analysis, complex abnormalities including -5/5q- and/or -7/7q- have two cases of secondary MDS and nine out of 14 cases of primary MDS. Complex chromosomal abnormalities did not improve following chemotherapy. In this study, clinical features and cytogenetic analysis demonstrated no significant difference between primary and secondary MDS.