We report a case of myelodysplastic syndrome (MDS), associated with prominent elliptocytosis. A 66-year-old male presented with peripheral pancytopenia, and was diagnosed with MDS [refractory anaemia (RA)]. Apart from marked elliptocytosis, dyshaematopoietic features were not evident in his peripheral blood or hypercellular bone marrow. After 18 months, he had progressed to RA with excess blasts in transformation. Analysis of red blood cell membrane proteins by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed a reduced quantity of protein 4.1 (30% of control). Deletion of chromosome 20q was identified by conventional cytogenetic analysis and fluorescence in situ hybridization. Marked elliptocytosis, persistent for more than 17 months, decreased strikingly after chemotherapy with idarubicin and Ara-C. These findings suggest that acquired elliptocytosis occurred as an unusual morphological feature of MDS, associated with abnormalities of protein 4.1 and chromosome 20q.

We report two cases that showed erroneous white blood cell differential counts by automated cell counters. Each case showed an interesting discrepancy of differential count between cell counters, and marked pseudobasophilia was observed by one of the two counters. The first patient was a 44-year-old female who suffered from multiple myeloma for more than one and a half years. Increased myeloma cells (43%) in peripheral blood were counted as basophils by the ADVIA 120, and as monocytes by SE-9000, respectively. The second patient was a 72-year-old female diagnosed as having chronic myelomonocytic leukemia. Dysgranulopoietic neutrophils (50%) and monocytes (31%) were increased in the peripheral blood. Dysgranulopoietic neutrophils were counted as basophils by STKS. In contrast, about half of the increased monocytes were counted as neutrophils by the ADVIA 120. These interesting findings highlight the importance of microscopic examination of the blood film in routine laboratory practice, and automated cell counters, especially for the hematologic patients, cannot completely substitute for it. These results also imply that at least some subpopulations with different membrane or cytoplasmic properties may exist even in the similarly classified cells.