Chronic neutrophilic leukemia

Overview

Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative disorder that features a persistent neutrophilia in peripheral blood, myeloid hyperplasia in bone marrow, hepatosplenomegaly, and the absence of the Philadelphia chromosome or a BCR/ABL fusion gene.

Symptoms

CNL characterize by sustained peripheral blood neutrophilia (>25 × 109 /L) and hepatosplenomegaly. The bone marrow is hypercellular. No significant dysplasia is in any of the cell lineages, and bone marrow fibrosis is uncommon.

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). There is no Philadelphia chromosome or BCR/ABL fusion gene. CNL is a slowly progressive disorder, and the survival of patients is variable, ranging from 6 months to more than 20 years.

Treatment

Until the last few years, the treatment of CNL focused on disease control rather than cure. Once the disease progressed to a more aggressive leukemia, there was typically little chance of obtaining a long-lasting remission because of the older age of most patients as well as the acquisition of multiple poor prognostic cytogenetic abnormalities. Allogeneic bone marrow transplantation represents a potentially curative treatment modality in the management of this disorder. Varying success has been reported with the use of traditional chemotherapies including hydroxyurea and interferon.