Effect of a combined aspiration and core biopsy technique on quality of core bone marrow specimens

For cases requiring both a bone marrow aspirate and core biopsy, using the same needle and site (i.e., a combined technique) can decrease time, expense, and discomfort compared with the independent (direct) collection of each specimen. The benefits of the combined approach should not be achieved at the expense of specimen quality. In this study, core bone marrow samples obtained from the proximal humerus of 26 dogs by a combined technique immediately posteuthanasia were compared with core samples obtained directly from the opposite humerus. Both core samples from each dog were compared for relative overall quality. Biopsies were unsuccessful in four dogs using the combined technique and in one dog by the direct technique. Marrow length was shorter and hemorrhage artifact was more common using the combined technique. There were no differences in cellularity, megakaryocyte count, the myeloid/erythroid ratio (M/E ratio), iron stores, or diagnostic quality. Direct core biopsy remains the ideal technique; however, the degree of compromise was small in the samples obtained from the combined technique. For clinical patients, the advantages of the combined technique must continue to be weighed against potential loss of diagnostic sensitivity.