ABSTRACT
BACKGROUND: Neutrophil nuclei in rodents may mature by ring formation. These cells are called ring neutrophils or doughnut cells. In man, small numbers of these mysterious cells may occur in myeloproliferative disease or in myelodysplastic syndrome (MDS). However, the incidence of ring neutrophils in the general population is unknown and their significance in disease states therefore remains obscure. METHODS: We have evaluated peripheral blood and bone marrow smears of patients with chronic myelogenous leukemia (CML), MDS, megaloblastic anemia, and these findings were compared with those of healthy controls. Only granulocytes with an unequivocal nuclear hole, not caused by superposition of nuclear lobes, were counted. To be counted, the hole should contain material with the same texture as the cytoplasm. Cells with hyposegmented nuclei were counted as well. Only distinct spectacle-like or peanut-shaped nuclei as well as the occasional single rounded nuclei were taken into account. RESULTS: 1) The number of patients enrolled was 58 (32 males and 26 females). The age ranged from 16 to 77 (mean 46) years. Twenty-eight cases of CML, 23 of MDS, 7 of megaloblastic anemia and 20 of healthy controls were included in this study. 2) In peripheral blood smears, the occurrence and numbers of ring neutrophils and hyposegmented cells were not significantly different between underlying diseases (P>0.05). In CML, as opposed to the control group, significantly more patients showed hyposegmented cells (P0.05). As compared with control group, there were no differences in the occurrence and numbers of ring neutrophils and hyposegmented cells (P>0.05). 4) Nuclear ring formation appeared to be significantly related to granulocytic hyposegmentation. CONCLUSION: These results suggest that ring neutrophils and hyposegmented cells can be nonspecifically found in patients with various hematologic diseases and healthy controls. To optimize the definite clinical significance of these cells, further studies will be needed.