Representative peripheral blood and BM smears from patients with refractory anemia with ring sideroblasts and marked thrombocytosis. (A) Peripheral blood smear showing thrombocytosis. May-Grünwald-Giemsa (MGG) staining; magnification, × 1000. (B) BM smear showing numerous clustered megakaryocytes that are markedly enlarged and similar to those observed in essential thrombocythemia. MGG staining; magnification, × 500. (C) BM smear showing erythroid hyperplasia with macro-megaloblastoid changes. MGG staining; magnification, × 1000. (D) BM smear after Perls staining showing numerous ring sideroblasts. Magnification, × 1000.