Neutrophil dysplasia is not a specific feature of the abnormal chromosomal clone 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 hybridization in combination with standard May-Grünwald-Giemsa morphology (MGG/FISH) to investigate the penetration of chromosomal abnormalities into dysplastic neutrophil granulocytes in five MDS patients with documented monosomy 7 or trisomy 8 in the bone marrow at diagnosis. Neutrophil dysplasia was defined as neutrophil granulocytes with extreme hypogranulation or with nuclear abnormalities of the pelgeroid type. In one patient all dysplastic cells 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 pelgeroid granulocytes exhibited the chromosomal marker. The results suggest that neutrophil dysplasia is not a specific feature of the abnormal chromosomal clone in MDS. It is not clear, however, if the disomic dysplastic cells were derived from a parallel MDS clone with a normal karyotype, or represent residual non-clonal, normal hematopoietic cells.