Coexistence of chronic neutrophilic leukemia with multiple myeloma

Chronic neutrophilic leukemia and atypical chronic myeloid leukemia: 2024 update on diagnosis, genetics, risk stratification, and management

Chronic neutrophilic leukemia (CNL) is a rare BCR::ABL1-negative myeloproliferative neoplasm (MPN) defined by persistent mature neutrophilic leukocytosis and bone marrow granulocyte hyperplasia. Atypical chronic myeloid leukemia (aCML) (myelodysplastic "[MDS]/MPN with neutrophilia" per World Health Organization [WHO]) is a MDS/MPN overlap disorder featuring dysplastic neutrophilia and circulating myeloid precursors. Both manifest with frequent hepatosplenomegaly and less commonly, bleeding, with high rates of leukemic transformation and death. The 2022 revised WHO classification conserved CNL diagnostic criteria of leukocytosis ≥25 × 109/L, neutrophils ≥80% with <10% circulating precursors, absence of dysplasia, and presence of an activating CSF3R mutation. ICC criteria are harmonized with those of other myeloid entities, with a key distinction being lower leukocytosis threshold (≥13 × 109/L) for cases CSF3R-mutated. Criteria for aCML include leukocytosis ≥13 × 109/L, dysgranulopoiesis, circulating myeloid precursors ≥10%, and at least one cytopenia for MDS-thresholds (ICC). In both classifications ASXL1 and SETBP1 (ICC), or SETBP1 ± ETNK1 (WHO) mutations can be used to support the diagnosis. Both diseases show hypercellular bone marrow due to a granulocytic proliferation, aCML distinguished by dysplasia in granulocytes ± other lineages. Absence of monocytosis, rare/no basophilia, or eosinophilia, <20% blasts, and exclusion of other MPN, MDS/MPN, and tyrosine kinase fusions, are mandated. Cytogenetic abnormalities are identified in ~1/3 of CNL and ~15-40% of aCML patients. The molecular signature of CNL is a driver mutation in colony-stimulating factor 3 receptor-classically T618I, documented in >80% of cases. Atypical CML harbors a complex genomic backdrop with high rates of recurrent somatic mutations in ASXL1, SETBP1, TET2, SRSF2, EZH2, and less frequently in ETNK1. Leukemic transformation rates are ~10-25% and 30-40% for CNL and aCML, respectively. Overall survival is poor: 15-31 months in CNL and 12-20 months in aCML. The Mayo Clinic CNL risk model for survival stratifies patients according to platelets <160 × 109/L (2 points), leukocytes >60 × 109/L (1 point), and ASXL1 mutation (1 point); distinguishing low- (0-1 points) versus high-risk (2-4 points) categories. The Mayo Clinic aCML risk model attributes 1 point each for: age >67 years, hemoglobin <10 g/dL, and TET2 mutation, delineating low- (0-1 risk factor) and high-risk (≥2 risk factors) subgroups. Management is risk-driven and symptom-directed, with no current standard of care. Most commonly used agents include hydroxyurea, interferon, Janus kinase inhibitors, and hypomethylating agents, though none are disease-modifying. Hematopoietic stem cell transplant is the only potentially curative modality and should be considered in eligible patients. Recent genetic profiling has disclosed CBL, CEBPA, EZH2, NRAS, TET2, and U2AF1 to represent high-risk mutations in both entities. Actionable mutations (NRAS/KRAS, ETNK1) have also been identified, supporting novel agents targeting involved pathways. Preclinical and clinical studies evaluating new drugs (e.g., fedratinib, phase 2) and combinations are detailed.

Chronic Neutrophilic Leukemia: A Comprehensive Review of Clinical Characteristics, Genetic Landscape and Management

Chronic neutrophilic leukemia (CNL) represents a rare disease, that has been classified among the BCR/ABL-negative myeloproliferative neoplasms. The disease is characterized by marked leukocytosis with absolute neutrophilia and its clinical presentation may vary from asymptomatic to highly symptomatic with massive splenomegaly and constitutional symptoms. CNL prognosis remains relatively poor, as most patients succumb to disease complications or transform to acute myeloid leukemia. Recent studies have demonstrated that CSF3R mutations drive the disease, albeit the presence of other secondary mutations perplex the genetic landscape of the disease. Notably, the presence of CSF3R mutations has been adopted as a criterion for diagnosis of CNL. Despite the vigorous research, the management of the disease remains suboptimal. Allogeneic stem cell transplantation represents the only treatment that could lead to cure; however, it is accompanied by high rates of treatment-related mortality. Recently, ruxolitinib has shown significant responses in patients with CNL; however, emergence of resistance might perturbate long-term management of the disease. The aim of this review is to summarize the clinical course and laboratory findings of CNL, highlight its pathogenesis and complex genetic landscape, and provide the context for the appropriate management of patients with CNL.

Chronic neutrophilic leukemia: 2022 update on diagnosis, genomic landscape, prognosis, and management

DISEASE OVERVIEW

Chronic neutrophilic leukemia (CNL) is a rare, often aggressive myeloproliferative neoplasm (MPN) defined by persistent mature neutrophilic leukocytosis, bone marrow granulocyte hyperplasia, and frequent hepatosplenomegaly. The 2013 seminal discovery of oncogenic driver mutations in colony-stimulating factor 3 receptor (CSF3R) in the majority of patients with CNL not only established its molecular pathogenesis but provided a diagnostic biomarker and rationale for pharmacological targeting.

DIAGNOSIS

In 2016, the World Health Organization (WHO) recognized activating CSF3R mutations as a central diagnostic feature of CNL. Other criteria include leukocytosis of ≥25 × 10⁹ /L comprising >80% neutrophils with <10% circulating precursors and rare blasts, and absence of dysplasia or monocytosis, while not fulfilling criteria for other MPN.

MANAGEMENT

There is currently no standard of care for management of CNL, due in large part to the rarity of disease and dearth of formal clinical trials. Most commonly used therapeutic agents include conventional oral chemotherapy (e.g., hydroxyurea), interferon, and Janus kinase (JAK) inhibitors, while hematopoietic stem cell transplant remains the only potentially curative modality.

DISEASE UPDATES

Increasingly comprehensive genetic profiling in CNL, including new data on clonal evolution, has disclosed a complex genomic landscape with additional mutations and combinations thereof driving disease progression and drug resistance. Although accurate prognostic stratification and therapeutic decision-making remain challenging in CNL, emerging data on molecular biomarkers and the addition of newer agents, such as JAK inhibitors, to the therapeutic arsenal, are paving the way toward greater standardization and improvement of patient care.

Chronic neutrophilic leukemia: 2020 update on diagnosis, molecular genetics, prognosis, and management

DISEASE OVERVIEW

Chronic neutrophilic leukemia (CNL) is a rare, often aggressive myeloproliferative neoplasm (MPN) defined by persistent mature neutrophilic leukocytosis, bone marrow granulocyte hyperplasia, and frequent hepatosplenomegaly. The seminal discovery of oncogenic driver mutations in colony-stimulating factor 3 receptor (CSF3R) in the majority of patients with CNL in 2013 anchored a new scientific framework, deepening our understanding of its molecular pathogenesis, providing a diagnostic biomarker, and rationalizing the use of pharmacological targeting.

DIAGNOSTIC CRITERIA

In 2016, the World Health Organization (WHO) included the presence of activating CSF3R mutations as a central diagnostic feature of CNL. Other criteria include leukocytosis of ≥25 × 10⁹ /L comprising >80% neutrophils with <10% circulating precursors and rare blasts, and absence of dysplasia or monocytosis, while not fulfilling criteria for other MPN.

DISEASE UPDATES

Increasingly comprehensive genetic profiling of CNL has disclosed a complex genomic landscape and additional prognostically relevant mutational combinations. Though prognostic determination and therapeutic decision-making remain challenging, emerging data on prognostic markers and the use of newer therapeutic agents, such as JAK inhibitors, are helping to define state-of-the-art management in CNL.

Chronic neutrophilic leukemia

Chronic neutrophilic leukemia is a rare myeloproliferative disorder characterized by a sustained peripheral blood neutrophilia, absence of the BCR/ABL oncoprotein, bone marrow hypercellularity with less than 5% myeloblasts and normal neutrophil maturation, and no dysplasia. This leukemia has been associated with mutations in the colony-stimulating factor 3 receptor (CSF3R) that may activate this receptor, leading to the proliferation of neutrophils that are the hallmark of chronic neutrophilic leukemia. We present a case of chronic neutrophilic leukemia and discuss the criteria for diagnosis and the significance of mutations found in this leukemia.

Recent Progress in Chronic Neutrophilic Leukemia and Atypical Chronic Myeloid Leukemia

PURPOSE OF REVIEW

We reviewed recent diagnostic and therapeutic progress in chronic neutrophilic leukemia (CNL) and atypical chronic myeloid leukemia (aCML). We summarized recent genetic data that may guide future efforts towards implementing risk-adapted therapy based on mutational profile and improving disease control and survival of affected patients.

RECENT FINDINGS

Recent genetic data in CNL and aCML prompted modifications to the World Health Organization (WHO) diagnostic criteria, which have improved our understanding of how CNL and aCML are different diseases despite sharing common findings of peripheral granulocytosis and marrow myeloid hyperplasia. The overlap of recurrently mutated genes between aCML and CMML support considering CSF3R-T618I mutated cases as a distinct entity, either as CNL or CNL with dysplasia. Ongoing preclinical and clinical studies will help to further inform the therapeutic approach to these diseases. Our understanding of CNL and aCML has greatly advanced over the last few years. This will improve clarity for the diagnosis of these diseases, provide a strategy for risk stratification, and guide risk-adapted therapy.

Chronic neutrophilic leukemia: new science and new diagnostic criteria

Chronic neutrophilic leukemia (CNL) is a distinct myeloproliferative neoplasm defined by persistent, predominantly mature neutrophil proliferation, marrow granulocyte hyperplasia, and frequent splenomegaly. The seminal discovery of oncogenic driver mutations in CSF3R in the majority of patients with CNL in 2013 generated a new scientific framework for this disease as it deepened our understanding of its molecular pathogenesis, provided a biomarker for diagnosis, and rationalized management using novel targeted therapies. Consequently, in 2016, the World Health Organization (WHO) revised the diagnostic criteria for CNL to reflect such changes in its genomic landscape, now including the presence of disease-defining activating CSF3R mutations as a key diagnostic component of CNL. In this communication, we provide a background on the history of CNL, its clinical and hemopathologic features, and its molecular anatomy, including relevant additional genetic lesions and their significance. We also outline the recently updated WHO diagnostic criteria for CNL. Further, the natural history of the disease is reviewed as well as potential prognostic variables. Finally, we summarize and discuss current treatment options as well as prospective novel therapeutic targets in hopes that they will yield meaningful improvements in patient management and outcomes.

Myeloproliferative masks of multiple myeloma: A review of literature and clinical case reports

Concurrences of multiple myeloma with myeloproliferative diseases or secondary myeloid leukemoid reactions are rather rare. The paper describes 3 cases of multiple myeloma: the first case concurrent with neutrophilic leukocytosis; the second case with secondary erythropoetin-dependent erythrocytosis, and the third case with chronic myeloid leukemia. In such cases, an accurate diagnosis requires molecular testing, besides routine clinical and laboratory studies. The paper discusses therapeutic strategy in cases of a concurrence of 2 competing tumors of the blood system: to treat them simultaneously or the most aggressive tumor now, as well as a relationship between multiple myeloma and chronic myeloid leukemia, other myeloproliferative disorders, and secondary myeloid leukemoid reactions.

[Chronic neutrophilic leukemia complicated with multiple myeloma: two cases report and literature review]

OBJECTIVE

To explored the diagnosis and treatment of chronic neutrophilic leukemia (CNL) complicated with multiple myeloma (MM).

METHODS

The clinical features and molecular biological characteristics of 2 patients with CNL complicated with MM were summarized, and the diagnosis and treatment of the patients were retrospectively reviewed.

RESULTS

The diagnosis of CNL complicated with MM was established in 2 cases. Case 1 had CSF3R mutation (P733T), but CSF3R-exon 14 mutation and SETBP1 mutation were all negative. The neutrophil count returned to normal when MM was successfully treated in case 1. When the patient relapsed, neutrophil count increased again.

CONCLUSION

Coexistence of CNL and MM is rare. CSF3R is a very important molecular marker for CNL. To the best of our knowledge, it's the first time to report the coexistence of CNL and MM carried CSF3R mutation (P733T). Chemotherapy regimens for MM may be effective in the treatment of CNL complicated with MM.

Chronic neutrophilic leukaemia and plasma cell-related neutrophilic leukaemoid reactions

Many cases reported as 'chronic neutrophilic leukaemia' have had an associated plasma cell neoplasm. Recent evidence suggests that the great majority of such cases represent a neutrophilic leukaemoid reaction to the underlying multiple myeloma or monoclonal gammopathy of undetermined significance. We have analysed all accessible reported cases to clarify the likely diagnosis and to ascertain whether toxic granulation, Döhle bodies and an increased neutrophil alkaline phosphatase score were useful in making a distinction between chronic neutrophilic leukaemia and a neutrophilic leukaemoid reaction. We established that all these changes occur in both conditions. Toxic granulation and Döhle bodies are more consistently present in leukaemoid reactions but also occur quite frequently in chronic neutrophilic leukaemia. The neutrophil alkaline phosphatase score is increased in both conditions and is of no value in making a distinction.

Chronic neutrophilic leukaemia

Chronic neutrophilic leukaemia (CNL) is a rare type of myeloproliferative neoplasm (MPN) characterised by sustained leucocytosis (≥25×10(9)/L) with neoplastic proliferation of neutrophilic granulocytes in blood and bone marrow. In contrast to chronic myeloid leukaemia, the disease primarily involves neutrophilic lineage with persistent proliferation of mature forms of neutrophils. No consistent cytogenetic changes have been reported. Known recurrent genetic changes in other MPNs such as JAK2, MPL, CALR, BCR-ABL1, PDGFRA, PDGFRB and FGFR1 are mostly absent. Recently, mutations in colony stimulating factor 3 receptor (CSF3R) have been reported in high frequency in CNL. This discovery has provided more insight into its pathogenesis and opened up possible treatment options. In this article, we review the clinical findings, morphology, pathobiology and differential diagnosis of CNL and treatment implications of CSF3R mutations.

Concurrent chronic neutrophilic leukemia blast crisis and multiple myeloma: A case report and literature review

The current study presents the case of a 78-year-old male with concurrent chronic neutrophilic leukemia (CNL) and multiple myeloma (MM) who developed acute myeloid leukemia after two years of treatment with hydroxyurea, cyclophosphamide, prednisone and thalidomide. The patient presented with mature neutrophilic leukocytosis, hepatosplenomegaly, a high neutrophil alkaline phosphatase score and an absence of the Philadelphia chromosome or the BCR-ABL fusion gene. A bone marrow aspirate smear and biopsy indicated that the CNL coexisted with a plasma cell neoplasm. In addition, monoclonal λ-paraproteinemia was detected by serum protein immunofixation electrophoresis, and bone lesions were identified in multiple vertebrae. The patient achieved complete remission following one cycle of induction chemotherapy with the decitabine regimen in combination with the low-dose cytarabine, aclarubicin and granulocyte-colony stimulating factor (CAG) priming regimen. The occurrence of CNL and MM concurrently is extremely rare and thus, it has only been reported in a small number of cases. The occurrence of CNL and MM in the same patient as two distinct hematological malignancies indicates the neoplastic transformation of a pluripotent stem cell. Decitabine combined with the CAG priming regimen may present a good therapeutic strategy for elderly patients with secondary acute myeloid leukemia.

Nephrotic syndrome related to chronic neutrophilic leukemia

Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative neoplasm. We herein describe the case of a 41-year-old woman who was admitted with nephrotic syndrome (NS) and severe neutrophilia and underwent a splenectomy due to splenomegaly. Peripheral blood tests revealed a Janus kinase 2 (JAK2) V617F mutation without the Philadelphia chromosome, BCR-ABL fusion transcripts, or FIP1 L1-platelet-derived growth factor (PDGF)a. A kidney biopsy showed focal segmental glomerulosclerosis (FSGS) with interstitial neutrophil infiltration and with a JAK2 V617F mutation. Hydroxyurea was initiated for first three months, followed by hydroxyurea plus interferon, and a subsequent improvement in leukocytosis and completely remission of FSGS-NS was immediately noted. This is the first case reported in which NS was related to CNL.

Simultaneous and sequential concurrent myeloproliferative and lymphoproliferative neoplasms

Concurrent manifestation of two chronic-stage myeloid and lymphoid/plasmacytoid neoplasms in one patient is rare and occurs in ≤1% of patients. There has been no systematic analysis of which combinations are frequent/infrequent and whether two concurrent diseases in one patient are clonally related or represent independent diseases. We therefore characterised a series of cases from our own archive (n = 65) and collected a large number of previously reported cases of patients in whom myeloid and lymphoid/plasmacytoid neoplasms co-occurred (n = 185). The most frequent combination was Philadelphia chromosome-negative myeloproliferative neoplasm with concurrent B cell chronic lymphocytic leukaemia, accounting for approximately 50% of double-disease patients. We compared the quantity of unsorted bone marrow cell-derived JAK2(V617F) and KIT(D816V) alleles with the quantity of the lymphoid/plasmacytoid compartment and analysed a subfraction of cases with fluorescence in situ hybridisation. Although a common aberrant progenitor has been reported in some cases in the literature, we found evidence of two independent chronic-stage myeloid and lymphoid/plasmacytoid neoplasms.

Monoclonal gammopathy of undetermined significance disguised as chronic neutrophilic leukemia

We encountered a 60-year-old woman with a medical history of diabetes mellitus, osteoporosis, peripheral vascular disease, and hypertension who had earlier presented at an outside facility with knee pain, which led to a finding of elevated neutrophil count of 35×10⁹/L. Because she was otherwise asymptomatic but continued showing elevated neutrophil levels, she sought a second opinion at our facility. Serum protein immunoelectrophoresis with immunofixation revealed an immunoglobulin A (IgA)-κ monoclonal gammopathy concentration of 1305 mg/dL (normal 80–350 mg/dL) but relatively normal concentrations of IgG of 840 mg/dL (620–1400 mg/dL) and IgM of 36 mg/dL (45–250 mg/dL). Using clonal analysis, we found a polyclonal expression pattern in all cell types analyzed. Comprehensive work-up for multiple myeloma and infectious etiology of neutrophilia was negative. We concluded that our patient’s neutrophilia may have been due to the underlying monoclonal gammopathy. This is the first case in the literature of a patient with monoclonal gammopathy of undetermined significance presenting with chronic neutrophilia, mimicking chronic neutrophilic leukemia (CNL). Patients with CNL have a poor prognosis; therefore, it is important to distinguish diagnostically between CNL and reactive neutrophilia.

Philadelphia chromosome-negative chronic myeloproliferative disease

Session 2 of the 2007 Workshop of the Society for Hematopathology/European Association for Haematopathology was focused on Philadelphia chromosome-negative chronic myeloproliferative diseases (Ph- MPDs), recently termed chronic myeloproliferative neoplasms. The presented and submitted cases highlighted some important issues and also impending problems associated with the diagnosis and classification. Cases included predominantly rare entities like chronic eosinophilic leukemia and related disorders, chronic neutrophilic leukemia, and others with specific genetic abnormalities that allowed molecularly targeted therapy. In this context, the distinctive role of a positive JAK2(V617F) mutation for the diagnosis of Ph- MPD was underscored, including entities with a low allele burden and the discrimination from reactive disorders (autoimmune myelofibrosis, reactive thrombocytosis). Although novel genetic and molecular approaches have significantly improved the way we classify Ph- MPD, a combined clinicopathologic approach, including representative bone marrow specimens, still remains the yardstick for diagnosis.

Nephrotic syndrome in a patient with IgM myeloma with associated neutrophilia

An unusual case having IgM monoclonal gammopathy with clinical and pathologic features of multiple myeloma (MM) in association with neutrophilia and nephrotic syndrome is reported. The patient showed lytic bone lesions, decreased IgG and IgA levels, Bence-Jones proteinuria, nephrotic proteinuria with edema, and histological plasma cell infiltration typical of MM. Moreover, mature neutrophilic leukocytosis, hepatomegaly, high leukocyte alkaline phosphatase score (LAP), absence of Philadelphia (Ph) chromosome and bcr gene rearrangement were also evidenced, all these features representing findings typical of the recently described plasma cell dyscrasia-associated neutrophilia. After the diagnosis, the patient was treated with melphalan and prednisone, with an excellent response to the treatment. Different from the 30 cases so far reported, this is the first case of plasma-cell dyscrasia with associated neutrophilia due to IgM-producing monoclonal gammopathy. At the same time, this is the first reported case of nephrotic syndrome secondary to IgM myeloma.

Pathology of the myeloproliferative diseases

The classification of myeloid neoplasms now includes CMPD, mixed CMPD/ MDS, MDS, and acute myeloid leukemias. CMPD and CMPD/MDS, both clonal stem cell diseases, share myeloproliferative features, including typical hypercellular marrows, organomegaly, and cell lineage maturation. The CMPD generally differ by which myeloid cell lineage dominates hematopoiesis, and the main diseases include CML, PV, ET, and CIM. The mixed CMPD/MDS disorders also show dysplastic features and variable amounts of effective hematopoiesis; these disorders include CMML, JMML, and atypical CML. Given the overlap in morphology among these diseases, correlation with clinical, hematologic, and cytogenetic/molecular genetic findings is imperative for precise classification.