Microscopic examination of bone marrow aspirate in healthy adults - comparison of two techniques of slide preparation.

INTRODUCTION: According to the International Council for Standardization in Hematology (ICSH) guidelines for the standardization of bone marrow specimens and reports, smears from bone marrow aspirates for microscopic examination should be prepared using two techniques simultaneously: the wedge-spread and the crush technique. However, the outcomes of these techniques have never been compared.

METHODS: We investigated the bone marrow of 105 adult, haematologically healthy subjects, using bone marrow smears prepared via both techniques simultaneously.

RESULTS: Comparison of the two techniques revealed significant differences in terms of the composition of bone marrow cells. Only the percentages of lymphocytes, mature eosinophils and basophils did not differ significantly. The reference ranges for each technique were established.

CONCLUSIONS: The crush technique seems to be more valuable than the wedge-spread technique because of the lack of a blood dilution effect and better assessment of megakaryopoiesis. We recommend the crush technique for the evaluation of the percentage composition of bone marrow cells. In a very small number of patients with irregular cell localization in the bone marrow particles, the wedge-spread technique may be more beneficial for the assessment of total cellularity. The recommendation to routinely prepare slides using both of these techniques is fully justified.