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

Table 1

Immunophenotype of blasts.

Marker		Expression on cells (blasts) in the blast gate
Positive	CD2	Dim to negative
	CD9	Positive
	CD13	Positive
	CD33	Positive
	CD34	Positive
	CD38	Dim to negative
	CD45	Positive
	CD58	Positive
	CD64	Positive
	CD117	Dim to negative
	CD123	Bright
	HLA_DR	Partial, subset
Negative	CD1a, CD3, cCD3, CD4, CD5, CD7, CD8, CD10, CD11b, CD11c, CD14, CD15, CD16, CD19, CD20, CD22, cCD22, CD25, CD42b, CD56, CD61, cCD79a, CD235a, kappa, lambda, TdT, cMPO, and cIgM