Secondary Logo

Journal Logo

Institutional members access full text with Ovid®

Chronic neutrophilic leukemia

novel mutations and their impact on clinical practice

Tefferi, Ayalew; Elliott, Michelle; Pardanani, Animesh

Current Opinion in Hematology: March 2015 - Volume 22 - Issue 2 - p 171–176
doi: 10.1097/MOH.0000000000000114
MYELOID DISEASE: Edited by Martin S. Tallman
Editor's Choice

Purpose of review Chronic neutrophilic leukemia (CNL) is a rare BCR-ABL1-negative myeloid malignancy that is characterized by mature granulocytosis without dysgranulopoiesis. Differential diagnosis of CNL includes reactive or secondary granulocytosis and other myeloid neoplasms, such as atypical chronic myeloid leukemia (aCML) and chronic myelomonocytic leukemia (CMML). Herein, we focus on recently described mutations in CNL and their impact on diagnosis, prognosis and treatment.

Recent findings In 2013, membrane-proximal CSF3R mutations, most frequently CSF3RT618I, were described in CNL and aCML. Subsequent studies confirmed the presence of such mutations in nearly all patients with CNL but not in aCML. Furthermore, the majority of the patients with CSF3R-mutated CNL also expressed other mutations, such as SETBP1 and ASXL1, which might be prognostically detrimental. Laboratory studies revealed that CSF3RT618I induced JAK inhibitor-sensitive activation of JAK-STAT and CNL-like disease in mice. Case reports have indicated palliative but not disease-modifying activity of JAK inhibitor therapy in CSF3R-mutated CNL.

Summary CNL is now a morphologically and molecularly defined myeloid malignancy, and no longer a diagnosis of exclusion. The identification of CNL-specific molecular markers provides a much needed pathogenetic insight and also offers the opportunity to revise current diagnostic criteria and identify prognostic biomarkers and potential drug targets.

Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA

Correspondence to Prof Ayalew Tefferi, MD, Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA. Tel: +1 507 284 3159; fax: +1 507 266 4972; e-mail:

Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.