Analysis of CSF3R mutations in atypical chronic myeloid leukemia and other myeloid malignancies.

We report a series of patients with CSF3R-mutant (CSF3Rmut) atypical chronic myeloid leukemia (aCML), chronic neutrophilic leukemia (CNL) or other hematologic malignancies. We included 25 patients: 5 aCML and 4 CNL CSF3Rmut patients; 1 aCML, 2 CNL, and 2 myelodysplastic/myeloproliferative neoplasm, not otherwise specified patients without CSF3R mutation; and 11 CSF3Rmut patients with other diseases [8 acute myeloid leukemia (AML), 1 chronic myelomonocytic leukemia (CMML), 1 myelodysplastic syndrome (MDS), and 1 acute lymphoblastic leukemia (ALL)]. Patients with aCML or CNL were tested by Sanger sequencing and pyrosequencing to identify CSF3R T618I. Twenty-two patients underwent gene panel analysis. CSF3R mutations, mostly T618I (8/9), were found at high frequencies in both aCML and CNL patients [5/6 aCML and 4/6 CNL]. Two aCML patients in early adulthood with CSF3R T618I and biallelic or homozygous CEBPA mutations without other mutations presented with increased blasts and exhibited remission for >6 years after transplantation. The other 7 CSF3Rmut aCML or CNL patients were elderly adults who all had ASXL1 mutations and frequently presented with SEBP1 and SRSF2 mutations. Five AML patients had CSF3R exon 14 or 15 point mutations, and 6 other patients (3 AML, 1 CMML, 1 MDS, and 1 ALL) had truncating mutations, demonstrating differences in leukocyte counts and mutation status. In conclusion, CSF3R mutations were found at a higher frequency in aCML patients than in previous studies, which might reflect ethnic differences. Additional studies are needed to confirm these findings and the relationship between CSF3R and CEBPA mutations.

[Chronic neutrophilic leukemia/chronic eosinophilic leukemia].

Chronic neutrophilic leukemia (CNL) is a clonal disorder that is characterized by increasing mature neutrophils. Colony stimulating factor 3 receptor (CSF3R) T618I mutation was frequently identified in patients with CNL and is defined as a molecular marker of the disease. Ruxolitinib, a JAK2 inhibitor, provided a promising therapeutic effect in a phase II study. In particular, ruxolitinib was more efficient for patients with CSF3R mutation. Allogeneic stem cell transplantation (Allo-SCT) may be a curative treatment for CNL. On the other hand, further studies are needed to define the optimal method of transplantation, source of donor, conditioning therapy, and timing of transplantation. Chronic eosinophilic leukemia (CEL) is a clonal disorder that is characterized by increasing eosinophils. In the World Health Organization Classification 5th edition, diagnostic criteria for CEL are renewed. Because the new criteria will be more specific for CEL than criteria in the older edition, "not otherwise specified (NOS) " is removed from the name of the disease. Anti-CD52 antibody, alemtuzumab, or anti-IL-5 antibody, mepolizumab, are promising drugs to control symptoms that are associated with hypereosinophilic syndrome. Allo-SCT is anticipated as a curative treatment for CEL, but the evidence of Allo-SCT for CEL is still limited. Further study is required to define the treatment strategy.

Extremely rare chronic neutrophilic leukemia characterized by unrelieved abdominal distention and swollen painful limbs: new clinical insight.

The pathogenesis of hematological tumors has not been fully elucidated. The academic community believes that genetic mutation abnormalities play a crucial role in the occurrence and development of hematological malignancies. Chronic neutrophilic leukemia (CNL) is a rare hematological tumor in the world. It is characterized by a Philadelphia chromosome BCR-ABL1-negative myeloproliferative tumor. It can be accompanied by mutations in various genes. Colony-stimulating factor 3 receptor (CSF3R) is a classic mutation in CNL and is included in the diagnostic criteria for CNL. This article described a 46-year-old male patient who came to the hospital with non-specific clinical manifestations such as unrelieved abdominal distension and edema of both lower extremities as the primary symptoms. The middle-aged male patient was provided with a peripheral a routine blood test. The biochemical tests revealed abnormalities. A bone marrow biopsy was performed to complete various tests such as bone marrow morphology, immunology, molecular biology, cytogenetics, and imaging. He was diagnosed with a rare chronic neutrophilic leukemia. After the diagnosis, the patient took ruxolitinib orally targeted therapy as prescribed by the doctor. Doctors regularly reviewed the peripheral blood examination and bone marrow status. The current condition is well controlled. CNL is extremely rare. The disease usually has non-specific clinical features and manifestations as the primary symptoms. These symptoms can easily be missed or lead to misdiagnosed ailments by clinicians. It is necessary to increase the awareness and vigilance of CNL.

Chronic neutrophilic leukemia preceded by myelodysplastic syndromes.

Chronic neutrophilic leukemia (CNL) is primarily diagnosed by excluding myelodysplastic syndromes (MDS). We report the case of a patient who developed secondary CNL 3 years after hypoplastic MDS. We used droplet digital polymerase chain reaction mutation detection assay to analyze genomic alterations during the progression from MDS to CNL. At the time of MDS diagnosis, U2AF1 Q157P and SETBP1 D868N were dominant and additional mutation of ASXL1 1934_insG was observed. CSF3R T618I and SETBP1 D868N were increasing at the time of CNL diagnosis. We revealed the accumulation of multiple gene mutations during CNL development from MDS. This suggests that CNL was clonally developed from the founding clone of MDS and CSF3R mutation contributes to the development of CNL in the present case. These findings provide insights into the pathology of CNL.

Autoimmune hemolytic anemia complicating a chronic neutrophilic leukemia: A case report of a rare association.

Key Clinical Message: Chronic neutrophilic leukemia is a rare disease with a poor prognosis. Its diagnosis is challenging in the lack of genetic tools. It can infrequently be associated with autoimmune hemolytic anemia. Abstract: Chronic neutrophilic leukemia is a rare disease with poor prognosis, characterized by a sustained mature neutrophilic leukocytosis in the absence of monocytosis or basophilia with few or no circulating immature granulocytes, hepatosplenomegaly, and granulocytic hyperplasia of the bone marrow. In addition, no molecular markers for other myeloproliferative neoplasms are detected. The 2016 WHO classification included the presence of the CSF3R mutation as a key diagnostic criterion for this disease. Although anemia may be present at diagnosis, hemolytic one rarely complicates myeloproliferative neoplasms. Treatment is largely based on cytoreductive agents, but bone marrow allograft remains the only curative option. We report the case of a patient with chronic neutrophilic leukemia associated with autoimmune hemolytic anemia. We describe the epidemiological, clinical, prognostic, and therapeutic features of this disease in addition to the difficulties of its diagnosis and management in Tunisia.

Advances in molecular evaluation of myeloproliferative neoplasms.

Myeloproliferative neoplasms (MPN) are a group of clonal hematopoietic stem cell disorders with uncontrolled proliferation of one or more hematopoietic cell types, including myeloid, erythroid and megakaryocytic lineages, and minimal defect in maturation. Most MPN are associated with well-defined molecular abnormalities involving genes that encode protein tyrosine kinases that lead to constitutive activation of the downstream signal transduction pathways and confer cells proliferative and survival advantage. Genome-wide sequencing analyses have discovered secondary cooperating mutations that are shared by most of the MPN subtypes as well as other myeloid neoplasms and play a major role in disease progression. Without appropriate management, the natural history of most MPN consists of an initial chronic phase and a terminal blast phase. Molecular aberrations involving protein tyrosine kinases have been used for the diagnosis, classification, detection of minimal/measurable residual disease, and target therapy. We review recent advances in molecular genetic aberrations in MPN with a focus on MPN associated with gene rearrangements or mutations involving tyrosine kinase pathways.

Case report: Chronic neutrophilic leukemia associated with monoclonal gammopathies. A case series and review of genetic characteristics and practical management.

Chronic neutrophilic leukemia (CNL) is a rare but potentially aggressive BCR::ABL1 negative myeloproliferative neoplasm, characterized by sustained mature, neutrophilic leukocytosis. The discovery of key driver mutations in the colony-stimulating-factor-3 receptor (CSF3R) gene resulted in the updated World Health Organization (WHO) diagnostic criteria in 2016. A significant number of CNL cases have been associated with plasma cell dyscrasias, predominantly multiple myeloma (MM) and monoclonal gammopathy of unknown significance (MGUS). Compared to pure CNL, mutated CSF3R is infrequently reported in CNL cases associated with monoclonal gammopathies (MG). Until now it remains unclear whether CNL and occurring plasma cell neoplasms are clonally related or CNL is developing secondary to the underlying dyscrasia. Owing to its rarity, currently no standard of care management exists for CNL and MG-associated CNL. In this case series we report the multi-center experience of five MG-associated CNL cases with a median age of diagnosis of 69 years. Three patients (66%) showed predominance of lambda light chain expression. Four (80%) eventually evolved to MM, and one CNL-MGUS patient developed secondary acute myeloid leukemia (AML). Mutated CSF3R was present in the patient who developed AML but was absent in other cases. To assess possible associated genetic aberrations we performed recurrent analysis with next-generation sequencing (NGS). Two patients (40%) deceased with a median time of survival of 8 years after CNL diagnosis. Three (60%) are currently in follow-up with no reoccurring leukocytosis. This case series, followed by a short review, provides a long-term clinical and genetic overview of five CNL cases associated with MG.

Case report: Leukemia cutis as the first manifestation of chronic neutrophilic leukemia in a 6-year-old girl.

Chronic neutrophilic leukemia (CNL) is a rare BCR-ABL negative myeloproliferative neoplasm that usually affects older adults with a poor prognosis. Leukemia cutis is an extramedullary manifestation of leukemia and may be misdiagnosed by dermatologists. Here, we describe a case of CNL in a 6-year-old Chinese girl with leukemia cutis as the first manifestation. Her skin rashes failed to attract the attention of dermatologists in early stages. The diagnosis was confirmed by peripheral smear, bone marrow studies, genomic analysis and skin biopsy.

Anti-inflammatory effects of ruxolitinib on chronic neutrophilic leukemia harboring CSF3R-T618I mutation with bilateral renal abscesses.

Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative neoplasm (MPN) characterized by sustained mature neutrophilic leukocytosis. Recently, presence of colony-stimulating factor 3 receptor (CSF3R) mutations has been added to the diagnostic criteria for CNL. Anti-inflammatory effects of the JAK1/2 inhibitor ruxolitinib relieve constitutional symptoms associated with MPN, such as fatigue, night sweats, and fever. We present a case of CNL harboring CSF3R-T618I mutation exacerbated by concomitant bilateral renal abscesses, which was refractory to antibiotics, at the time of initial diagnosis. In this case, ruxolitinib rapidly improved not only CNL but the infection, due to its anti-inflammatory potency.

Allogeneic Hematopoietic Stem Cell Transplantation for Mixed or Overlap Myelodysplastic/Myeloproliferative Disorders.

Chronic myelomonocytic leukemia (CMML) and the remaining, less frequent hybrid, mixed, or overlap myelodysplastic syndromes/myeloproliferative neoplasms (MDSs/MPNs) are difficult to treat neoplastic hematological disorders, exhibiting substantial clinical and prognostic heterogeneity, for which clear therapeutic guidelines or effective treatment options are still missing. CMML has an overall survival ranging from a few months to several years. Although patients with proliferative or dysplastic features may benefit from hydroxyurea and hypomethylating agent treatment, respectively, none of these treatments can establish long-term remission and prevent the inevitable transformation to acute leukemia. Novel targeted treatment approaches are emerging but are still under investigation. Therefore, currently, allogeneic stem cell transplantation (allo-SCT) remains the only treatment modality with a curative potential, but its widespread application is limited, due to significant morbidity and mortality associated with the procedure, especially in the elderly and in patients with comorbidities. Recognition of patient eligibility for allo-SCT is crucial, and the procedure should be addressed to patients with a good performance status without severe comorbidities and mainly to those in intermediate- to high-risk category, with a suitable stem cell donor available. The issues of best timing for performing transplantation, patient and donor eligibility, the type of conditioning regimen, and the outcomes after various allo-SCT procedures are the topics of this review.

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.

Rare evolution of CSF3R-mutated chronic neutrophilic leukemia to t(4;12)(q12;p13) acute myeloid leukemia with SETBP1 mutation.

Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative disease accompanied by mutations in CSF3R. Here, we present a patient with CNL who developed to acute myeloid leukemia (AML) at the same time that a t(4;12)(q12;p13) translocation appeared. The uniqueness of this cytogenetic abnormality led us to delineate the molecular aberrations relevant for clonal evolution. While the CSF3R mutation was present throughout the course of the disease, the SETBP1 mutation was newly acquired at the AML transformation. The present case suggests that careful monitoring of t(4;12)(q12;p13) and SETBP1 is crucial to predict AML evolution in CNL patients.

CSF3R T618I mutated chronic myelomonocytic leukemia: A proliferative subtype with a distinct mutational profile.

Chronic myelomonocytic leukemia (CMML) is a clonal myeloid neoplasm characterized by sustained monocytosis and mutations in TET2, ASXL1, SRSF2, SETBP1, NRAS, and KRAS. We describe a rare case of CSF3R T618I mutated CMML that has a proliferative phenotype, myelodysplasia, and additional mutations in ASXL1, SETBP1, KRAS, and PTPN11. Comparing the clinicopathologic features of this case to previously reported cases of CSF3R T618I mutated CMML and CSF3R non-T618I mutated CMML, CSF3R T618I seems to define a unique proliferative subtype of CMML with a distinct mutational profile. The diagnostic challenges and molecular pathogenesis associated with this case are also briefly discussed.

Co-Occurring CSF3R W791* Germline and Somatic T618I Driver Mutations Induce Early CNL and Clonal Progression to Mixed Phenotype Acute Leukemia.

Chronic neutrophilic leukemia (CNL) relates to mutational CSF3R activation with membrane proximal CSF3R mutations such as T618I as driver mutations, but the significance of truncating mutations is not clarified. In CNL, concomitant mutations promote disease progression, but insight into longitudinal acquisition is incomplete. In this study, we investigated the role of co-occurring germline and somatic CSF3R mutations in CNL, and assessed the impact of clonal evolution on transformation to acute leukemia. We employed sequential next generation sequencing and SNP array karyotyping to assess clonal evolution in CNL of early manifestation age based on a 33-year-old patient. Germline vs. somatic mutations were differentiated using a sample from the hair follicle. To investigate a potential predisposition for CNL development and progression by germline CSF3R-W791*, allelic localizations were evaluated. We detected a somatic CSF3R-T618I mutation at 46% variant allele frequency (VAF) at the time of CNL diagnosis, which co-occurred with a CSF3R-W791* truncation at 50% VAF in the germline. Evaluation of allelic localization revealed CSF3R-T618I and W791* on the same allele. A concomitant ASXL1 mutation at 39% VAF increased to 48% VAF upon transformation to mixed phenotype acute leukemia (MPAL), which has both myeloid and lymphoid features. Clonal evolution further involved expansion of the CSF3R double-mutant clone to 90% VAF via copy neutral loss of heterozygosity on chromosome 1p and the emergence of a RUNX1 mutant subclone. Allogeneic transplantation induced complete remission. This study highlights that CNL not only transforms to AML but also to MPAL. The molecular evolution is especially interesting with a CSF3R-W791* mutation in the germline and acquisition of CSF3R-T618I on the same allele compatible with increased susceptibility for mutation acquisition facilitating RUNX1-related clonal transformation.

Skin Rash as the First Manifestation of Pediatric Chronic Neutrophilic Leukemia / 罕见病研究

A 6-year-old girl presented with recurrent skin rash at the initial stage, recent joint pain, and neutrophilia was found during a routine blood test. After a multidisciplinary case discussion, she was diagnosed with chronic neutrophil leukemia, and the symptoms were relieved after hydroxyurea and luxolitinib treatment. She received the allogeneic hematopoietic stem cell transplantation subsequently. At present, she is in stable condition and under follow-up. Chronic neutrophil leukemia is a rare disease, which rarely occurs in children. It is more difficult to diagnose in patients with skin rash as the first manifestation. The diagnosis and treatment of this case reflects the important role of multidisciplinary cooperation in the diagnosis and treatment of difficult and rare diseases.

Chronic Neutrophilic Leukemia: A Literature Review of the Rare Myeloproliferative Pathology.

Hematological malignancies often develop due to a vast spectrum of environmental and genetic etiologies. Chronic neutrophilic leukemia (CNL) can be described as a BCR-ABL1 (Philadelphia chromosome)-negative myeloproliferative neoplastic disease with various genetic mutations that may directly or indirectly play a role in its pathogenesis. A well-established mutation in CNL is the CSF3R (a cytokine receptor) which has been incorporated into the diagnostic criteria for the disease. However, evidence of other mutations such as SETBP1, ASXL1, and TET2 has also shed more light on the pathogenesis of this condition. Due to the unknown incidence and heterogeneous presentation of the disease, the diagnosis and management are often difficult and lack satisfactory data. The purpose of this review is to yield further insight into a disease that lacks awareness in the medical community. Using PubMed as a database, relevant studies and case reports were reviewed. The data compiled were used to acknowledge the disease in terms of etiology, clinical manifestation, molecular pathogenesis, and available treatment modalities. Though existing treatment modalities have been shown to induce clinical improvement, the outcomes are not reliable, and further research is required to reach a comprehensive "standard of care" for the disease.

A Case of Chronic Neutrophilic Leukemia Incidentally Detected by 18F-FDG PET/CT.

Chronic neutrophilic leukemia (CNL) is a rare, potentially aggressive, myeloproliferative neoplasm. To the best of our knowledge, there are no previous reports dealing with 18F-FDG PET findings in CNL. We describe a case of CNL in a 69-year-old male, imaged with 18F-FDG PET/CT at diagnosis and during treatment.