Loss of blast heterogeneity in myelodysplastic syndrome and other chronic myeloid neoplasms.

OBJECTIVES Flow cytometry immunophenotyping has been suggested as an adjunctive technique in the evaluation of myeloid malignancies, especially in the myelodysplastic syndromes. However, its use has been limited due to complexity and cost restraints. The goal of this study is to attempt a simpler approach to flow cytometry immunophenotyping in myeloid neoplasms. METHODS We analyzed bone marrow specimens of 45 selected patients and an additional 99 consecutive random patients using a limited antibody panel. RESULTS Normal CD34-positive blasts show a characteristic pattern of CD13/HLA-DR expression, with three readily identifiable subpopulations. In contrast, myeloid neoplasms frequently show loss of this heterogeneity. CONCLUSIONS Analysis of a limited antibody panel with a focus on CD13/HLA-DR expression provides relatively high specificity and sensitivity for the detection of myeloid neoplasms.