Immature Erythroid Precursors and/or Erythrocyte Dysplasia in Peripheral Blood.

BACKGROUND: With the progress of technology in automated hematology analyzers, in the vast majority of cases, nucleated red corpuscles (NRC) can be automatically identified by most types of automated hematology analyzers, thus correcting the leukocyte count and avoiding pseudoleukocytosis by the analyzers themselves. The objective of the study was to explore pseudoleukocytosis due to immature erythroid precursors and/or erythrocyte dysplasia in the peripheral blood resulting from different rare situations. METHODS: Four rare cases showing pseudoleukocytosis due to immature erythroid precursors and/or erythrocyte dysplasia in the peripheral blood were analyzed and the effects on complete blood count (CBC) performed on a Sysmex XN-2000 analyzer and microscopic morphological features of the peripheral blood were investigated. These cases were selected for their vital value in describing all pseudoleukocytosis due to immature erythroid pre-cursors and/or erythrocyte dysplasia in the peripheral blood. The causes of immature erythroid precursors and/or erythrocyte dysplasia in the peripheral blood were analyzed. RESULTS: In all these cases, proportions of NRC and leukocyte counts were affected to varying degrees by the presence of numerous immature erythroid precursors and/or obvious erythrocyte dysplasia in the peripheral blood. All cases associated with an alarm concerning NRC presentation, and abnormal scattergrams of WDF and WNR, thus leading to pseudoleukocytosis. CONCLUSIONS: Laboratory artifacts led by NRC may be an indicator towards the occurrence of numerous immature erythroid precursors and/or obvious erythrocyte dysplasia in the peripheral blood, and active extramedullary hematopoiesis, breakdown of the bone marrow barrier, and the stress response of acute bleeding and severe multiple infection.