Table 1.

Summary of 2008 WHO diagnostic criteria

	Chronic myeloid leukemia* (chronic phase)	Atypical chronic myeloid leukemia	Chronic neutrophilic leukemia†
Blood
WBC	nd	>13 × 10e9/L	>25 × 10e9/L
Neutrophils and bands	nd	nd	>80%
Immature granulocytes‡	≥10%	≥10%	<10%
Basophilia	Present	Minimal or <2% of leukocytes	nd
Myeloblasts	Usually <2%	<20%	<1%
Marrow
Granulocytic hyperplasia	Present	Present	Present
Myeloblasts	Usually <5%	<20%	<5%
Granulocytic dysplasia	Minimal/absent	Prominent	Minimal/absent
Megakaryocytic dysplasia	Usually present*	May or may not be present	Minimal/absent
Other
Hepatosplenomegaly	nd	nd	Present
BCR-ABL or variant transcripts	Present	Absent	Absent
PDGFRA, PDGFRB, or FGFR1 rearrangements	Absent	Absent	Absent
PV, PMF, or ET by WHO criteria	No	No	No
Monocytosis >1 × 10e9/L	Absent	Absent	Absent

nd, not defined.

^*90%–95% have the t(9;22)(q34;q11.2) there are rare cases of variant translocations or cryptic translocations; absolute basophilia is invariably present and eosinophilia is common. Small, hypolobated megakaryocytes (“dwarf megakaryocytes”) are usually present.

^†In the absence of a clonal cytogenetic or molecular marker, rule out reactive neutrophilia and an underlying tumor.

^‡Promyelocytes, myelocytes, and metamyelocytes.