(A) Diagnostic blasts with a high nucleocytoplasmic ratio and scant agranular cytoplasm (Giemsa stain, ×1,000). (B) Regenerating blasts are larger with moderate granular cytoplasm (Giemsa stain, ×1,000). (C-F) Immunophenotyping showing the regenerating blasts positive for CD45, CD34, CD13, and CD33 and negative for CD19 and CD10.