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.

CSF3R-mutant chronic myelomonocytic leukemia is a distinct clinically subset with abysmal prognosis: a case report and systematic review of the literature

Chronic myelomonocytic leukemia (CMML) is a myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) chacaterized by persistent peripheral blood monocytosis, hypercellular bone marrow and dysplasia at least in one myeloid lineage. CMML shares much of its molecular landscape with other myeloid neoplasms, while differs from others such as chronic neutrophilic leukemia (CNL), given the high frequency of CSF3R mutations in the latter. In this article, we report a case of CSF3R-mutated CMML and dissect this rare entity by reviewing the medical literature, with the intent to understand how this rare mutation shapes CMML's clinical and morphological phenotype. CSF3R-mutated CMML emerges as a rare entity meeting the ICC/WHO diagnostic criteria for CMML and simultaneously showing clinical-pathological and molecular traits of CNL and atypical chronic myeloid leukemia, rising an important and difficult diagnostic and therapeutical issue.

Mutational screens highlight glycosylation as a modulator of colony-stimulating factor 3 receptor (CSF3R) activity

The colony-stimulating factor 3 receptor (CSF3R) controls the growth of neutrophils, the most abundant type of white blood cell. In healthy neutrophils, signaling is dependent on CSF3R binding to its ligand, CSF3. A single amino acid mutation in CSF3R, T618I, instead allows for constitutive, ligand-independent cell growth and leads to a rare type of cancer called chronic neutrophilic leukemia. However, the disease mechanism is not well understood. Here, we investigated why this threonine to isoleucine substitution is the predominant mutation in chronic neutrophilic leukemia and how it leads to uncontrolled neutrophil growth. Using protein domain mapping, we demonstrated that the single CSF3R domain containing residue 618 is sufficient for ligand-independent activity. We then applied an unbiased mutational screening strategy focused on this domain and found that activating mutations are enriched at sites normally occupied by asparagine, threonine, and serine residues-the three amino acids which are commonly glycosylated. We confirmed glycosylation at multiple CSF3R residues by mass spectrometry, including the presence of GalNAc and Gal-GalNAc glycans at WT threonine 618. Using the same approach applied to other cell surface receptors, we identified an activating mutation, S489F, in the interleukin-31 receptor alpha chain. Combined, these results suggest a role for glycosylated hotspot residues in regulating receptor signaling, mutation of which can lead to ligand-independent, uncontrolled activity and human disease.

CNL and aCML should be considered as a single entity based on molecular profiles and outcomes

Chronic neutrophilic leukemia (CNL) and atypical chronic myeloid leukemia (aCML) are rare myeloid disorders that are challenging with regard to diagnosis and clinical management. To study the similarities and differences between these disorders, we undertook a multicenter international study of one of the largest case series (CNL, n = 24; aCML, n = 37 cases, respectively), focusing on the clinical and mutational profiles (n = 53 with molecular data) of these diseases. We found no differences in clinical presentations or outcomes of both entities. As previously described, both CNL and aCML share a complex mutational profile with mutations in genes involved in epigenetic regulation, splicing, and signaling pathways. Apart from CSF3R, only EZH2 and TET2 were differentially mutated between them. The molecular profiles support the notion of CNL and aCML being a continuum of the same disease that may fit best within the myelodysplastic/myeloproliferative neoplasms. We identified 4 high-risk mutated genes, specifically CEBPA (β = 2.26, hazard ratio [HR] = 9.54, P = .003), EZH2 (β = 1.12, HR = 3.062, P = .009), NRAS (β = 1.29, HR = 3.63, P = .048), and U2AF1 (β = 1.75, HR = 5.74, P = .013) using multivariate analysis. Our findings underscore the relevance of molecular-risk classification in CNL/aCML as well as the importance of CSF3R mutations in these diseases.

Diagnosis and management of neutrophilic myeloid neoplasms

Chronic neutrophilia is commonly seen with persistent infections, inflammatory disorders, smoking, solid tumors, and specific medications. However, after reactive causes have been excluded, a workup for primary (clonal) neutrophilic disorders, such as myeloproliferative neoplasms (MPNs) and myelodysplastic/myeloproliferative overlap syndromes, should be pursued. Except for chronic myeloid leukemia, which is defined by the presence of the Philadelphia (Ph) chromosome, and the classic Ph chromosome-negative MPNs (polycythemia vera, essential thrombocythemia, and primary myelofibrosis), clonal neutrophilic neoplasms historically have been challenging to diagnose and classify. The 2016 revised World Health Organization classification of these disorders has been based mainly on clinicopathologic features. However, recent discoveries of the molecular alterations underlying these disorders have served to supplement our knowledge of their morphologic and clinical features, opening new therapeutic avenues. In this review, we discuss the diagnostic approach, prognostic features, and treatments of neutrophilic myeloid neoplasms, with a focus on chronic neutrophilic leukemia, atypical chronic myeloid leukemia, and chronic myelomonocytic leukemia.

[Fatal intracerebral hemorrhage in a patient with chronic neutrophilic leukemia: About one case and literature review]

INTRODUCTION

Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative syndrome characterized by a significant increase in mature neutrophils. One of the most serious complications is the occurrence of bleeding events, which may sometimes lead to death.

CASE REPORT

A 75-year-old patient presented with CNL, complicated by a severe bleeding phenotype. Biological investigations revealed platelet function defect and increase in neutrophil elastase. The follow-up was marked by an intracranial hemorrhage leading to the patient's death 7 months after diagnosis.

CONCLUSION

This bleeding phenotype has been reported several times in patients with CNL. However, the pathophysiological mechanisms that cause bleeding are not yet fully understood.

Genomic landscape of neutrophilic leukemias of ambiguous diagnosis

Chronic neutrophilic leukemia (CNL), atypical chronic myeloid leukemia (aCML), and myelodysplastic/myeloproliferative neoplasms, unclassifiable (MDS/MPN-U) are a group of rare and heterogeneous myeloid disorders. There is strong morphologic resemblance among these distinct diagnostic entities as well as a lack of specific molecular markers and limited understanding of disease pathogenesis, which has made diagnosis challenging in certain cases. The treatment has remained empirical, resulting in dismal outcomes. We, therefore, performed whole-exome and RNA sequencing of these rare hematologic malignancies and present the most complete survey of the genomic landscape of these diseases to date. We observed a diversity of combinatorial mutational patterns that generally do not cluster within any one diagnosis. Gene expression analysis reveals enrichment, but not cosegregation, of clinical and genetic disease features with transcriptional clusters. In conclusion, these groups of diseases represent a continuum of related diseases rather than discrete diagnostic entities.

[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.

What's different about atypical CML and chronic neutrophilic leukemia?

Atypical chronic myeloid leukemia (aCML) and chronic neutrophilic leukemia (CNL) are rare myeloid neoplasms defined largely by morphologic criteria. The discovery of CSF3R mutations in aCML and CNL have prompted a more comprehensive genetic profiling of these disorders. These studies have revealed aCML to be a genetically more heterogeneous disease than CNL, however, several groups have reported that SETBP1 and ASXL1 mutations occur at a high frequency and carry prognostic value in both diseases. We also report a novel finding-our study reveals a high frequency of U2AF1 mutations at codon Q157 associated with CSF3R mutant myeloid neoplasms. Collectively, these findings will refine the WHO diagnostic criteria of aCML and CNL and help us understand the genetic lesions and dysregulated signaling pathways contributing to disease development. Novel therapies that emerge from these genetic findings will need to be investigated in the setting of a clinical trial to determine the safety and efficacy of targeting various oncogenic drivers, such as JAK1/2 inhibition in CSF3R-T618I-positive aCML and CNL. In summary, recent advances in the genetic characterization of CNL and aCML are instrumental toward the development of new lines of therapy for these rare leukemias that lack an established standard of care and are historically associated with a poor prognosis.

Current strategies in the diagnosis and management of chronic neutrophilic leukemia

OBJECTIVE

To review the implications for diagnosis, pathogenesis and potential for new therapeutic option for chronic neutrophilic leukemia (CNL).

DATA SOURCES

Data cited in this review were obtained mainly from PubMed and Medline from 1993 to 2013 and highly regarded older publications were also included. The terms "chronic neutrophilic leukemia" and "diagnosis" were used for the literature search.

STUDY SELECTION

We identified, retrieved and reviewed the information on the clinical and laboratory features, the new genetic findings, prognosis and disease evolution and management of CNL.

RESULTS

The discovery of high-frequency granulocyte-colony stimulating factor receptor (CSF3R) mutations in CNL identifies a new major diagnostic criterion, and lends more specificity to the World Health Organization (WHO) diagnostic criteria for CNL, which are variably applied in routine clinical practice.

CONCLUSIONS

In patients for whom the cause of neutrophilia is not easily discerned, the incorporation of CSF3R mutation testing can be a useful point-of-care diagnostic to evaluate the presence of a clonal myeloid disorder, as well as providing the potential for genetically informed therapy. The oncogenic CSF3R mutations are molecular markers of sensitivity to inhibitors of the SRC family-TNK2 and JAK kinases and may provide a new avenue for therapy.

Oncogenic CSF3R mutations in chronic neutrophilic leukemia and atypical CML

BACKGROUND

The molecular causes of many hematologic cancers remain unclear. Among these cancers are chronic neutrophilic leukemia (CNL) and atypical (BCR-ABL1-negative) chronic myeloid leukemia (CML), both of which are diagnosed on the basis of neoplastic expansion of granulocytic cells and exclusion of genetic drivers that are known to occur in other myeloproliferative neoplasms and myeloproliferative-myelodysplastic overlap neoplasms.

METHODS

To identify potential genetic drivers in these disorders, we used an integrated approach of deep sequencing coupled with the screening of primary leukemia cells obtained from patients with CNL or atypical CML against panels of tyrosine kinase-specific small interfering RNAs or small-molecule kinase inhibitors. We validated candidate oncogenes using in vitro transformation assays, and drug sensitivities were validated with the use of assays of primary-cell colonies.

RESULTS

We identified activating mutations in the gene encoding the receptor for colony-stimulating factor 3 (CSF3R) in 16 of 27 patients (59%) with CNL or atypical CML. These mutations segregate within two distinct regions of CSF3R and lead to preferential downstream kinase signaling through SRC family-TNK2 or JAK kinases and differential sensitivity to kinase inhibitors. A patient with CNL carrying a JAK-activating CSF3R mutation had marked clinical improvement after the administration of the JAK1/2 inhibitor ruxolitinib.

CONCLUSIONS

Mutations in CSF3R are common in patients with CNL or atypical CML and represent a potentially useful criterion for diagnosing these neoplasms. (Funded by the Leukemia and Lymphoma Society and others.).

Chronic neutrophilic leukaemia: an Egyptian case

Chronic neutrophilic leukaemia (CNL) is a rare myeloproliferative disorder of elderly patients characterised by sustained neutrophilia. The diagnosis of CNL requires the exclusion of BCR/ABL positive chronic myelogenous leukaemia and leukemoid reaction. We present here a case of a 61-year-old Egyptian man with CNL and 21 months of follow-up. The main symptom of our patient was purpura. Splenomegaly, hepatomegaly and lymph node enlargement were not detected at presentation or throughout the patient's course. Thrombocytopenia was a considerable problem in our patient, causing recurrent bleeding and affecting the hydroxyurea dose adjustment. While hydroxyurea decreased the total leucocytic count, it could not affect the fatal course of the disease. The survival course of our patient extended to 21 months after presentation. The cause of death was attributed to disease progression.

Miliary tuberculosis associated with chronic neutrophilic leukemia

We report a case of miliary tuberculosis associated with chronic neutrophilic leukemia (CNL). A 70-year-old woman was referred to our hospital complaining of a 1-month history of persistent fever and anorexia. Chest and abdominal computed tomography images revealed diffuse small nodular lesions in the bilateral lung fields and extreme splenomegaly. Sputum cultures isolated Mycobacterium tuberculosis. After anti-tuberculous therapy for 1 year, the patient underwent splenectomy for massive splenomegaly and progressive leukocytosis. The presence of the homozygous JAK2 V617F tyrosine kinase mutation was also demonstrated in the peripheral blood. She was finally diagnosed as having miliary tuberculosis associated with CNL based on the histopathological examination of spleen. The patient was treated with a daily dose of 500 mg of hydroxyurea. As a result, 18 months after the splenectomy, her leukocyte count was decreased and her clinical condition was markedly improved; there was no relapse of the CNL.

Myeloproliferative syndromes: diagnosis and therapeutic options

Myeloproliferative syndromes (MPS) are clonal proliferation of hematopoietic progenitor cells characterized by proliferation of 1 or a few cell lines such as granulocytic, erythroid, megakaryocytic or mastocytic. These syndromes include: chronic myeloid leukemia, polycythemia vera, essential thrombocythemia, myelofibrosis, chronic eosinophilic leukemia/hypereosinophilic syndrome, chronic neutrophilic leukemia and systemic mastocytosis. Diagnosis of MPS is often difficult due to need of differential diagnosis with reactive proliferation caused by primarily non-hematological factors. Differentiation of individual MPS forms is also difficult because of overlapping of particular clinical or laboratory adnormalities. Discovery of specific molecular aberrations in the last few years facilitates diagnostic procedures. The discovered gene mutations or their fusions are associated with production of proteins possessing tyrosine kinase properties. These discoveries resulted in the successful introduction of the targeted therapy with tyrosine kinase inhibitors in the recent years.

Chronic neutrophilic leukaemia

Chronic neutrophilic leukaemia is a rare myeloproliferative disease characterised by splenomegaly, sustained neutrophilia, raised vitamin B12 level and absence of the Philadelphia chromosome. We report a 74-year-old man who presented first with Sweet's syndrome and subsequently leukocytosis. He had splenomegaly, a raised vitamin B12 level, serum uric acid and neutrophil alkaline phosphatase score. Cytogenetic study of the marrow was normal and peripheral blood for BCR-ABL gene transcript was not detectable. He subsequently passed away with bronchopneumonia.

Rare presentation of leucocytosis

We present the case of a 44 years man who presented to us with persistent leucocytosis. Following relevant investigations, we diagnosed him to have Chronic Neutrophilic Leukaemia (CNL); a rare haematological disorder. Ten months later, he remains non-responsive to standard line of treatment.

Chronic neutrophilic leukemia and chronic myelomonocytic leukemia: WHO defined

The World Health Organization (WHO) classification of myeloid disorders has provided updated parameters for the consistent diagnosis of two previously less than optimally defined chronic myeloid disorders, CNL and CMML. The classification of these disorders, which had been controversial, is now better defined and provides more clinically and biologically relevant disease definitions to enable uniform diagnosis and a framework to evaluate natural history and therapeutic interventions. CNL is now recognized as a distinct entity among the chronic myeloproliferative disorders and CMML is included within the new category of 'myelodysplastic/myeloproliferative diseases' (MDS/MPD). Predominant neutrophilia defines CNL whereas CMML is defined by predominant and monocytosis. In each case these defining features must be distinguished from reactive causes for the same in the absence of clear evidence of myeloid clonality (CNL and CMML) or dysplasia (CMML). The exclusion of underlying bcr/abl-driven oncogenesis is an essential component in the diagnosis of these chronic leukemic processes. The optimal therapy for both CNL and CMML remains uncertain. Current management decisions are based on small studies or extrapolated from therapeutic strategies that are effective in similar chronic, clonal myeloid disorders. Given the potential for evolution to acute leukemia or progressive refractory leucocytosis or cytopenias, allogeneic stem cell transplantation might be appropriate for younger patients. Continued reporting and investigation of specific therapeutic strategies and responses must be encouraged.

[Chronic neutrophilic leukemia: a long-term analysis of seven cases and review of the literature]

Chronic neutrophilic leukemia is an uncommon hematological entity. According to the WHO classification it is recognized as part of the family of myeloproliferative disorders. In the last 20 years seven patients have been diagnosed with chronic neutrophilic leukemia at our department. All but one had splenomegaly, two patients developed severe anaemia and in one case thrombocytosis was present at the time of diagnosis. White blood cell count ranged between 39 x 10(9)/1-71 x 10(9)/l with 80% of neutrophils and striking myeloid hyperplasia were present in the bone marrow without evidence of any dysplasia resembling chronic myelocytic leukemia. Granulocyte alkaline phosphatase scores were increased except one case and both cytogenetics (Philadelphia chromosome) and molecular biologic analysis (bcr/abl) revealed no alteration of any. Four patients have been followed up. Three of them died due to progression of chronic neutrophilic leukemia. One patient, initially receiving hydroxyurea + interferon therapy and showing progression, developed complete hematological remission with an eight week imatinib mesylate (Glivec) treatment. Beside of their own experiences the authors review the current literature and discuss differential diagnostic and therapeutic challenges, as well.

Chronic neutrophilic leukemia: a contemporary review

Chronic neutrophilic leukemia (CNL) is recognized as a distinct clinicopathologic entity characterized by sustained mature neutrophilic leukocytosis splenomegaly with bone marrow granulocytic hyperplasia without evidence of dysplasia or striking reticulin fibrosis. This diagnosis is contingent on thorough initial investigation and follow-up to exclude underlying causes of reactive neutrophilia, particularly if evidence of myeloid clonality is lacking. The optimal therapy for CNL remains uncertain. Current management decisions are based on anecdotal reports or extrapolated from therapeutic strategies effective in similar chronic clonal myeloid disorders. Because of the potential for blastic transformation and progressive refractory neutrophilia, allogeneic stem cell transplantation may be appropriate for younger patients. Continued reporting of all cases of CNL and responses to therapeutic strategies must be encouraged.

Evidence of clonality in chronic neutrophilic leukaemia

BACKGROUND

Chronic neutrophilic leukaemia (CNL) is a rare myeloproliferative disorder of elderly patients characterised by sustained neutrophilia and splenomegaly. The diagnosis of CNL requires the exclusion of BCR/ABL positive chronic myelogenous leukaemia (CML) and of leukaemoid reactions (LRs). The differentiation between CNL and LR is problematic because both conditions share similar morphological features; it is also important because patients with CNL generally have a poor prognosis.

AIMS

To determine whether CNL and LR could be distinguished on the basis of different clonality patterns.

METHODS

Blood samples from 52 women were studied using the human androgen receptor gene assay (HUMARA).

RESULTS

Monoclonality was found in the neutrophils in all 17 patients with different myeloproliferative syndromes (MPSs), including those with CNL. In four of the patients with CNL, autologous T cells were also monoclonal, suggesting that they belonged to the neoplastic clone. This finding was in contrast to other MPSs in which T cells were almost always polyclonal. Of nine patients with clinically suspected LR, the neutrophils of five were polyclonal, whereas three patients had monoclonal neutrophils, suggesting that they might be in the process of developing an MPS. Among 26 healthy blood donors, 20 had polyclonal neutrophils and five showed skewed clonality patterns. One case of LR and one normal blood donor were scored "not informative" at the HUMARA locus.

CONCLUSIONS

Clonality studies of blood neutrophils using HUMARA aid in distinguishing female patients with monoclonal CNL from those with LR. For the diagnosis of CNL, monoclonality of the neutrophils should be demonstrated whenever possible.

Chronic neutrophilic leukaemia: 14 new cases of an uncommon myeloproliferative disease

BACKGROUND

Chronic neutrophilic leukaemia (CNL) is a distinct BCR/ABL negative myeloproliferative disorder of elderly patients characterised by sustained neutrophilia and splenomegaly. The bone marrow shows expansion of neutrophilic granulopoiesis, without excess of myeloblasts. To date, only 129 cases of CNL have been reported in the literature.

AIMS

To report the findings from a large group of 14 new cases of CNL, consisting of eight women and six men (mean age, 64.7 years).

METHODS

A review of the 14 new cases of CNL and the investigation of BCR/ABL translocations in these patients.

RESULTS

Three quarters of the patients died within two years after diagnosis, mostly as a result of severe cerebral haemorrhage. Two younger patients were successfully treated with allogeneic bone marrow transplantation or interferon, which resulted in haematological remission for years.

CONCLUSION

CNL is a rare myeloproliferative disease mostly taking a fatal clinical course, despite the presence of mature neutrophils as leukaemic cells in the blood. Thus, it is important to recognise CNL to develop appropriate therapeutic strategies for affected patients.

Allogeneic bone marrow transplantation in the management of chronic neutrophilic leukemia

Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative disorder characterized by a clonal proliferation of mainly mature neutrophils, which is often difficult to differentiate from reactive leukocytosis or other myeloproliferative disorders. Treatment to date has focused on disease control rather than cure. Once the disease has progressed to a more aggressive leukemia there is typically little chance of obtaining a long lasting remission due to the older age of most patients as well as the acquisition of multiple poor prognostic cytogenetic abnormalities. In this case report we describe a successful sibling allogeneic bone marrow transplant in a 60-year-old man with CNL performed while he was still in the stable phase of his disease. We propose that even in older patients this curative approach may be considered in selected patients at an early stage of their disease, similar to the approach taken with chronic myelogenous leukemia.

Coexistence of chronic neutrophilic leukemia with multiple myeloma

A case report of simultaneous presentation of chronic neutrophilic leukemia and multiple myeloma (IgG kappa) in a 71-year-old male is described. The patient showed mature neutrophilic leukocytosis, hepatosplenomegaly, high neutrophil alkaline phosphatase score, hyperuricemia, neutrophils with toxic granulation and Döhle bodies, absence of Philadelphia chromosome and of the bcr-abl fusion gene. Moreover, a monoclonal IgG kappa paraproteinemia (36.93 g l(-1)) was detected. Bence-Jones proteinuria was 3.84 g l(-1). The bone marrow was grossly hypercellular with marked myeloid hyperplasia and aggregates of plasma cells. The patient died of severe bronchopneumonia after the transformation of chronic neutrophilic leukemia to acute myelomonocytic leukemia, 1.5 years following diagnosis.

[Differential diagnosis of chronic myeloid leukemia and the related disorders]

Chronic myeloid leukemia(CML) is a generic term that includes five subtypes; i.e. chronic granulocytic leukemia(CGL) (95% of all CML, 90% are Ph+, 5% are Ph-, BCR/ABL+), atypical CML(survival is worse than that of CGL), chronic myelomonocytic leukemia(a subtype of myelodysplastic syndrome), chronic neutrophilic leukemia (Ph-, BCR/ABL-) and juvenile CML(Ph-, BCR/ABL-). It is not so easy to make a diagnosis of Ph-negative CML. Also, about 25% of adult acute lymphoid leukemia(ALL) patients and some essential thrombocythemia patients have Ph chromosome. In addition, about a half of cases with Ph-positive ALL have the same size of BCR/ABL fusion protein as that in Ph-positive CML. It is necessary to distinguish them by the distinctive morphological, cytogenetical and immunological characteristics of these diseases.

Chronic neutrophilic leukemia--a case report

Chronic neutrophilic leukemia is a rare hematological disorder with hepatosplenomegaly and sustained mature neutrophilic leucocytosis. Increased serum vitamin B12, increased serum urine acid levels and increased leukocyte alkaline phosphatase activity are the associated features in the absence of fever or any other underlying disorder to cause leukemoid reaction. We report one such rare case.

Transition of polycythemia vera to chronic neutrophilic leukemia

Two cases of polycythemia vera (PV) had transition to a hematological condition compatible with chronic neutrophilic leukemia (CNL) 17 and 8 years after diagnosis, respectively. One patient was treated with carboquone followed by hydroxyurea (HU) and the other with HU during PV phase. On transition, both had neutrophilia with white blood cell count above 40,000/microl, elevated neutrophil alkaline phosphatase activity, splenomegaly, normal karyotype without bcr-abl rearrangement. Busulfan was temporally effective in controlling the neutrophil count. However, one patient progressed to the so-called spent phase and the other subsequently had multiple transitions between PV and CNL. These cases may represent a form of uncommon evolution of PV and support the contention that CNL is a type of myeloproliferative disorder and that at least some CNL cases have derangement at the hematopoietic stem cell level.

Coexistence of chronic neutrophilic leukemia with light chain myeloma

A 60-year-old woman who presented with weakness, night sweats, bone pain, easy bruising and weight loss was found to have ecchymoses and hepatosplenomegaly. Blood counts showed persistent neutrophilia of mature cell type with Döhle bodies and toxic granulation. Coexistence of chronic neutrophilic leukemia and multiple myeloma of kappa light chain type was documented by bone marrow examination and immunofixation.

Neutrophilic dermatosis associated with chronic neutrophilic leukemia

Chronic neutrophilic leukemia is an uncommon myeloproliferative disorder. We report a new case that fulfills the clinical and biologic criteria for such a diagnosis. The hematologic disease was revealed by a neutrophilic dermatosis that finally disappeared spontaneously after a duration of 1 year. Despite the lack of parallelism in the course of dermatologic and hematologic manifestations, we believe they were strongly linked. Occurrence of neutrophilic dermatoses in the course of other myeloproliferative disorders is well known. However, in our case, clinical and histologic features could not be used to distinguish between atypical Sweet's syndrome and specific cutaneous lesions because of the mature appearance of both skin and blood neutrophils.

[Chronic neutrophilic leukemia: apropos of 2 cases and review of the literature]

Two patients with chronic neutrophilic leukemia, a rare myeloproliferative syndrome, are reported with a review of the literature. The major features of the 34 collected cases (including the two patients reported here) were persistent leukocytosis simulating a leukemoid reaction, hepatosplenomegaly, hyperuricemia, increased vitamin B12 blood level, increased leukocyte alkaline phosphatase and absence of the Philadelphia chromosome. Infection was the leading cause of death. Concomitant multiple myeloma was found in eight patients.

Chronic neutrophilic leukemia--report of a case and review of the literature

A male patient, aged 78, was found with chronic neutrophilic leukemia (CNL). The patient showed sustained mature neutrophilic leukocytosis, splenomegaly, a high leukocyte alkaline phosphatase score, elevated serum vitamin B12 and uric acid, myeloid hyperplasia and absence of ph' chromosome in the bone marrow, with no evidence suggesting this condition to be a leukemoid reaction to an underlying disease. In addition to the above mentioned features, some functional characteristics of CNL cells were compared with normal cells. CNL is a very rare disease; some thought it as a variant of chronic myelogenous leukemia (CML). In this report a review of the literature is also included.