Pseudobasophilia as an erroneous white blood cell differential count with a discrepancy between automated cell counters: report of two cases

Abstract

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.

Comparison of abnormal cell flagging of the hematology analyzers Sysmex XN and Sysmex XE‐5000 in oncohematologic patients

“…flag, corresponded to atypical lymphocytes. Similar cases have been detected in other analyzers . In our group of 111 lymphoproliferative diseases, we detected four cases of pseudobasophilia in the XE‐5000 analyzer (2 a‐CLL and 2 Sézary syndrome) and only one case in the XN analyzer.…”

Flowcytometric analysis of basophil counts in human blood and inaccuracy of hematology analyzers

“…Although the Bayer ADVIA ® ‐120 (and possibly other analyzers using a technique based on the resistance of basophils to acid stripping) normally gives at least an approximation of basophils counts, they may be subject to other errors in certain conditions. For example it has been shown that myeloma cells in the blood of patients are counted as basophils by this analyzer (19). Since lower numbers of plasma cells are observed in the blood, e.g.…”

Accurate basophils counting: not an easy goal!

“…Sir , we read with interest the paper ‘Pseudobasophilia as an erroneous white blood cell differential count with a discrepancy between automated cell counters’ by Hur et al. (2004) published in the last issue of Clinical and Laboratory Haematology.…”