Chronic neutrophilic leukemia (CNL)

Correlation of clinical history, hematologic data, morphology of the blood and bone marrow, and cytogenetic and molecular genetic data is necessary to reach the diagnosis of CNL. This can be problematic because of the overlap of its morphologic findings with those of infection, inflammation, and other myeloid neoplasms.
CNL is characterized by sustained, mature neutrophilic leukocytosis with no or only few circulating immature granulocytes. There is no monocytosis or basophilia. Bone marrow reveals granulocytic hyperplasia without evidence of dysplasia.
Philadelphia chromosome (Ph chromosome) and/or its molecular counterpart, fusion of bcr and abl genes are not present. In addition, features of other myeloproliferative neoplasms; chronic myelogenous leukemia (CML), atypical CML (aCML), and CMML, as defined by the WHO, must be absent
Other causes, such as malignancy or infection, capable of causing a leukemoid reaction, should be excluded.

Diagnstic criteria