Chronic Neutrophilic Leukemia

Definition

Reactive neutrophilia must be ruled out
- Infections
- Inflammatory processes
- Underlying neoplasm
  - Most common is plasma cell myeloma
Sustained peripheral blood leukocytosis with neutrophilia
- WBC ≥25 x 10³/μL
- Segmented neutrophils and bands >80% (usually >95%)
  - May have toxic granulation
  - No dysplasia
- Immature granulocytes <10%
- Blasts <1%
Hypercellular bone marrow
- Myeloid hyperplasia
  - Myeloblasts <5%
  - Normal granulocytic maturation
  - Megakaryocytes normal or left shifted
Hepatosplenomegaly
No Ph' or BCR-ABL1 or rearrangement of PDGFRA, PDGFRB or FGFR1
- CML with p230 BCR-ABL1 is neutrophilic variant of CML, not CNL
PV, PMF, ET, MDS and MDS/MPN must be excluded

Dita Gratzinger MD PhD
Tracy I George MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342

Original posting: 10/23/11