[Chromosome 21 rearrangement in a case of therapy-related myelodysplastic syndrome in multiple myeloma].

A case of therapy-related myelodysplastic syndromes (t-MDS) in 66-year-old male patient is reported. The patient was diagnosed as having multiple myeloma in July 1983. Cyclophosphamide was given since September 1984, and melphalan was added since June 1986. Radiation therapy was not performed. Mild, slowly aggravating pancytopenia developed in July 1987. By December 1987, the hemoglobin level dropped to 6.0 g/dl, leukocytes to 2,800/microliters, and platelets to 15,000/microliters. At that time, 27% of the bone marrow cells were blasts and 23.3% monocytoid cells. Based on these findings, a diagnosis of t-MDS was made. He was managed by supportive care only, but the monocytoid cells increased rapidly in number and he died of pulmonary bleeding in March 1988. Chromosomal banding studies of the bone marrow cells revealed dir ins [inv (17) (p13q21); 21] (q21; p13q22) in all the 11 metaphases examined, but chromosomes No. 5 and 7 were normal. However, Keldsen et al reported that chromosome 21q rearrangements were nonrandomly associated with t-MDS and t-acute nonlymphocytic leukemia.