Table 1

WHO Diagnostic Criteria		Patient Data	Comparison
aCML	CNL	Patient Data	CNL (√/X)	aCML (√/X)
WBCs ≥ 13x10⁹/L with dysgranulopoiesis	WBCs ≥ 25x10⁹/L with segmented neutrophils >80% of WBCs^a	WBCs 125x10⁹/L with >80% neutrophils and no dysgranulopoiesis	√	X
Hypercellular marrowb	Hypercellular marrow^c	Hypercellular marrow with mature forms	√	√
No Ph or BCR-ABL1 fusion gene	No Ph or BCR-ABL1 fusion gene	No Ph or BCR-ABL1 fusion gene	√	√
No rearrangement PDGFRα/β	No rearrangement PDGFRα/β or FGFR1	No rearrangement PDGFRα/β or FGFR1	√	√
Blood neutrophil precursors ≥ 10% of WBCs	Hepatosplenomegaly	Blood neutrophil precursors <10% WBCs	√	X
Minimal basophilia (<2%)	No physiologic cause for neutrophilia	No basophilia in blood or marrow	√	√
Minimal monocytosis (<10%)	No evidence of PV, ET, or PM	Monocytes 3%	√	√
Less than 20% blasts in blood and marrow	No evidence of MDS or MDS/MPD	Less than 20% blasts in blood and marrow	√	√
		Hepatosplenomegaly (mild)	√	X
		No physiologic cause for neutrophilia	√	√
		No evidence of PV, ET, or PM	√	√
		No evidence of MDS or MDS/MPD	√	√

Table 1: World Health Organization (WHO) diagnostic criteria for chronic neutrophilic leukemia (CNL) and atypical chronic myelogenous leukemia (aCML) with corresponding patient clinical/laboratory data.

Abbreviations: WHO = World Health Organization; CNL = chronic neutrophilic leukemia; aCML = atypical chronic myelogenous leukemia, BCR-ABL1 negative; WBC = white blood cell; Ph = Philadelphia chromosome; PDGRF = platelet-derived growth factor receptor; FGFR = fibroblast growth factor receptor; PV = polycythemia vera; ET = essential thrombocythemia; PM = primary myelofibrosis; MDS = myelodysplastic syndrome; MPD = myeloproliferative disorder; v = patient meets criterion; X = patient does not meet criterion.

a. segmented neutrophils and band forms are >80% of WBCs, immature granulocytes <10% of WBCs, and myeloblasts <1% of WBCs. b. granulocytic proliferation and granulocytic dysplasia with or without dysplasia in the erythroid and megakaryocytic lineages. c. neutrophilic granulocytes increased in percentage and number with myeloblasts <5% of nucleated marrow cells, normal neutrophil maturation pattern, and megakaryocytes normal or left shifted [1].