Cytogenetic Studies in Patients with Acute Myeloid Leukemia Following a Myelodysplastic Syndrome.

Between 1981 and 1988, thirty-nine patients with acute myeloid leukemia (AML) following a de novo myelodysplastic syndrome (n-MDS) were studied cytogenetically. The chromosomal aberration rate was 59%. The anomalies most often found were: complex (four or more) aberrations (n = 6), a 5q- chromosome (n = 6), monosomy 7 or a 7q- chromosome and trisomy 8 as the sole defect (n = 3). Incidence and types of chromosomal aberrations were approximately the same as in myelodysplastic syndromes and in 191 patients with de novo AML studied in our laboratory during the same period. But the cytogenetic pattern in AML post de novo MDS also shared certain similarities with chromosomal findings in 35 patients with secondary, therapy-induced (t) AML/MDS. In both these types of acute leukemia primary changes such as t(8;21), t(15;17) and inv (16) were not found; the frequency of AA-Karyotypes was high (70 and 66%) and the incidence of -5,5q- in AML post de novo MDS was more comparable with that found in t-AML/MDS than in de novo AML. Thus the chromosomal patterns seen in AML post de novo MDS indicate that these leukemias share similarities with both de novo and t-AML not only clinically but also cytogenetically.