Bone Marrow Aspiration: Normal Hematopoiesis and Basic Interpretive Procedures

Diagnostic bone marrow samples are usually obtained by hematology or oncology practitioners. Bone marrow aspirate smears from these samples are usually prepared by the: (Choose all that apply)

Collecting clinician Hematology/Pathology laboratory staff Feedback Bone marrow smears are prepared at the patient bedside either by the clinician collecting the sample, or by the laboratory technologist who is present during the procedure. When bone marrow samples are delivered to the laboratory, the hematology or pathology laboratory technologists may prepare the bone marrow smears.

Which of the following bone marrow smear techniques would be advisable if only a small bone marrow sample is obtained?

Coverslip preparation

Correctly order the steps involved in performing a bone marrow differential.

Feedback The process of performing a bone marrow differential involves the following steps: Record patient and sample information. Check for fragments. Review stain and smear quality. Scan for tumor cells, cellularity, megakaryocytes etc. Add oil and perform differential. Calculate M:E ratio, record cellularity, megakaryocytes etc. Send to hematopathologist for final review and interpretation.

Which of the following is an important technique in order to obtain consistently high quality bone marrow smears?

Select or concentrate bone marrow spicules, ensuring they are transferred to the slide.

An assessment of the myeloid to erythroid (M:E) ratio is part of every bone marrow evaluation. Select the choices below that apply to the M:E ratio.

The erythroid tally/total used in calculating the M:E ratio is the sum of all the nucleated red cell precursors. White blood cells used in the myeloid tally/total used to calculate the M:E ratio include neutrophil precursors as well as eosinophil precursors and basophil precursors. Lymphocytes and monocytes/histiocytes are not counted in the evaluation of the M:E ratio. The M:E should always be interpreted in context with the overall bone marrow cellularity.