Peripheral blood smears of myelodysplasia patients: scanning electron microscope findings

The utility of scanning electron microscopy in the evaluation of ordinary glass peripheral blood smears of patients with myelodysplasia and those uncertain for myelodysplasia is emphasized. Attention is directed to changes in segmented granulocytes. Comparison of ultrastructural findings in abnormal blood smears with control cases is made. Important findings include reduced cytoplasmic granule number, increased cell size, large cytoplasmic vacuoles, condensation of the peripheral cytoplasm, prominence of large cytoplasmic granules, irregular cytoplasmic perimeter, abnormal nuclear morphology, abnormal cell shape, and a necklace-like arrangement of cytoplasmic granules. Of these findings, reduced cytoplasmic granule number was the most specific finding, while condensation of peripheral cytoplasm was the most sensitive. Combination of these two morphologic findings may provide a strong predictor of myelodysplasia. The study included a limited test of unknown cases evaluated by one author, including two uncertain for myelodysplasia. Pitfalls in evaluating temporary pancytopenia not associated with myelodysplasia are noted.