Comparison of touch imprints with aspirate smears for evaluating bone marrow specimens

We compared the differential counts of normal and abnormal bone marrow from touch imprints with those from aspirate smears to determine whether the touch imprint was reliable for independent routine use in the examination of bone marrow and the classification of hematologic abnormalities. Normocellular bone marrow specimens were obtained from 87 patients without hematologic abnormality. Abnormal bone marrow specimens were obtained from 173 patients with treated or untreated neoplastic hematologic disease, including acute myeloid leukemia, myelodysplastic syndrome, chronic lymphocytic leukemia, non-Hodgkin lymphoma, hairy cell leukemia, myeloma, and acute lymphoblastic leukemia. We found no diagnostic difference in the differential counts from touch imprints and aspirate smears of normocellular bone marrow, and although we found some difference between the differential counts in certain cases of diseased bone marrow, the touch imprint proved to be a reliable diagnostic tool for determining the cellular composition of normal bone marrow and more reliable for the diagnosis of bone marrow involved by a neoplastic hematologic disease. Our findings suggest that evaluating touch imprints should be considered a standard practice in examining bone marrow.