Disease Overview for Chronic Neutrophilic Leukemia (CNL)

CNL is a rare chronic myeloproliferative neoplasm of unknown etiology, characterized by sustained peripheral blood neutrophilia (>25 × 109/L) and hepatosplenomegaly.[1,2] The bone marrow is hypercellular in patients with CNL. No significant dysplasia is in any of the cell lineages, and bone marrow fibrosis is uncommon.[1,2] Cytogenetic studies are normal in nearly 90% of the patients. In the remaining patients, clonal karyotypic abnormalities may include +8, +9, del (20q) and del(11q).[1,3-5] There is no Philadelphia chromosome or BCR::ABL fusion gene. CNL is a slowly progressive disorder, and the survival of patients ranges from 6 months to more than 20 years.