Neutrophil dysplasia is not a specific feature of the abnormal chromosomalclone in myelodysplastic syndromes

In order to study if dysplastic cells are part of the abnormal chromosomal clone in myelodysplastic syndromes (MDS) we used fluorescence in situ hybri dization in combination with standard May-Grunwald-Giemsa morphology (MGG/F ISH) to investigate the penetration of chromosomal abnormalities into dyspl astic neutrophil granulocytes in five MDS patients with documented monosomy 7 or trisomy 8 in the bone marrow at diagnosis. Neutrophil dysplasia was d efined as neutrophil granulocytes with extreme hypogranulation or with nucl ear abnormalities of the pelgeroid type. In one patient all dysplastic cell s were derived from the abnormal chromosomal clone, while in the other four cases only 6-43% of the hypogranulated neutrophils and 33-40% of the pelge roid granulocytes exhibited the chromosomal marker. The results suggest tha t neutrophil dysplasia is not a specific feature of the abnormal chromosoma l clone in MDS. It is not clear, however, if the disomic dysplastic cells w ere derived from a parallel MDS clone with a normal karyotype, or represent residual non-clonal, normal hematopoietic cells. (C) 1999 Elsevier Science Ltd. All rights reserved.