Intra-leukocytic hemosiderin inclusions detected as pseudoeosinophils by automated depolarization analysis in a patient with beta-thalassaemia major and immune hemolysis

This report describes a patient with intra-leukocytic hemosiderin inclusions associated with iron overload and acute infection. These inclusions resulted in a false identification of eosinophils rather than neutrophils using an automated analyzer. The analyzer interpreted the aberrant increased depolarization as a reflection of eosinophils. No eosinophils were found by examination of the blood smear. The implications for the hematology morphologist is that visual inspection of a blood smear is nearly always indicated whenever any departure from strict normality is noted in the output from an automated blood cell counter.