MPO Expression of Background Neutrophils in MPO Negative Acute Promyelocytic Leukemia, An Easy Clue to Corroborate a Challenging Diagnosis: A Case Report and Review of Literature

Figure 2

Blast population (aqua) gated based on (a) forward scatter and side scatter with (b) dimmer CD45 in a 10-color flow cytometric evaluation. Pertinent scatter plots show gated blasts are (c) positive for CD34 and CD117 (dim to negative), (d) positive for CD13 and CD33, (e) negative for CD22 and cMPO (cytoplasmic myeloperoxidase), (f) positive for CD64 and negative for CD14, (g) dim to negative for CD2 and negative for CD1a, and (h) partially positive (subset) for HLA-DR and negative for CD11c.

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