PERIPHERAL-BLOOD PICTURE IN PRIMARY HYPOCELLULAR REFRACTORY-ANEMIA AND IDIOPATHIC ACQUIRED APLASTIC-ANEMIA - AN ADDITIONAL TOOL FOR DIFFERENTIAL-DIAGNOSIS

Background and Objective. Hypoplastic myelodysplastic syndromes (MDS) are being reported with increasing frequency. Aplastic anemia (AA) nee ds to be differentiated from hypoplastic MDS particularly primary hypo plastic refractory anemia (PHRA) because of the impact on management a nd prognosis. This distinction may be morphologically difficult even w ith careful marrow examination which may provide insufficient material due to extreme hypocellularity. The value of peripheral blood (PB) pa rameters ill making the distinction between AA and PHRA is not well st udied. In this work, we attempt to examine peripheral blood findings a s an additional tool for differentiating PHRA from acquired idiopathic AA. Methods. PB findings in ten cases of PHRA, which are selected bas ed on the following: less than 30% cellularity, multilineage dysplasia and/or clonal cytogenetic abnormality, are compared to ten cases of c lassic AA. The PB is examined for automated parameters, differential w hite cell count, morphologic changes in red cells, white cells, platel ets, and the presence of circulating blasts, megakaryocytic fragments and micromegakaryocytes. Results. AA patients tend to have lower plate let and monocytic counts and higher lymphocytic percentages. The follo wing morphologic findings are seen only in PHRA but not in AA: hypochr omic red cells, left shift, circulating blasts, hypersegmentation with long filaments, hypogranular, ring, and pelgeroid neutrophils, Dohle bodies, circulating micromegakaryocytes and megakaryocytic fragments. Interpretation and Conclusions. We conclude that careful examination o f peripheral blood may provide sufficient information to allow for the distinction between PHRA and AA early in the course of the disease. S imilarly, patients with classic AA who subsequently develop unusual bl ood findings during routine follow up should be suspected of having a clonal evolution which needs to be confirmed by marrow examination and cytogenetic analysis. (C) 1997, Ferrata Storti Foundation.