A systematic classification of megakaryocytic dysplasia and its impact on prognosis for patients with myelodysplastic syndromes

We performed CD41 immune staining and proposed a systematic classification of dys-megakaryopoiesis on bone marrow films: (1) micro-megakaryocytes (<12 µm); (2) micro-megakaryocytes (12–40 µm) with 1 nucleus; (3) micro-megakaryocytes (12–40 µm) with 2 nuclei; (4) micro-megakaryocytes (12–40 um) with multiple (more than 2) nuclei; (5) dysplastic megakaryocytes (≥40 µm) with 1 nucleus; (6) dysplastic megakaryocytes (≥40 µm) with 2 nuclei; and (7) dysplastic megakaryocytes (≥40 µm) with multiple (more than 2) nuclei. Further, we evaluated the prognostic impact of micro-megakaryocytes and dysplastic mono-nucleated megakaryocytes on MDS patients. The best discriminator cut-off point for each group was determined by the minimal P value approach. In multivariate analyses micro-megakaryocytes ≥25 % and dysplastic mono-nucleated megakaryocytes ≥30 % were independent adverse prognostic factors (hazard ratio [HR] = 1.58 [95 % confidence interval [CI], 1.11, 2.23]; P = 0.010 and 1.53 [1.09, 2.16]; P = 0.014).