RESUMEN
A standard bone marrow examination may be done in patients with a known nonhematologic malignancy in order to evaluate the presence or absence of metastatic disease. A 300-cell-count differential of the aspirate is often performed in these cases. However, the clinical utility of the differential count has never been assessed. A retrospective review was performed on 107 bone marrow reports from 86 patients with a documented nonhematologic malignancy to determine the clinical usefulness of the differential counts in this patient population. Two cases out of 107 had clinically relevant findings from the aspirate differential. One patient had an increase in plasma cells (7%) and one had left-shifted granulopoiesis with 19% blasts. In most instances, the performance of an aspirate differential adds little clinically useful information in patients undergoing bone marrow examination for metastatic disease. There are cost savings associated with omitting the routine aspirate differential as either technologist- or pathologist-time in performing the differential is decreased.