Reliability of the DI-60 Digital Image Analyzer for Detecting Platelet Clumping and Obtaining Accurate Platelet Counts

Pseudothrombocytopenia caused by platelet clumping (PC) can lead to unnecessary platelet transfusions or underdiagnosis of hematologic neoplasms. To overcome these limitations, we assessed the capacity of the Sysmex DI-60 digital morphology analyzer (Sysmex, Kobe, Japan) for detecting PC and determining an accurate platelet count in the presence of PC. For this purpose, 135 samples with or without PC (groups Y and N, respectively) were processed by an examiner (a hematologic specialist) using both the Sysmex XN-9000 and DI-60 analyzers. Although the platelet aggregate (PA) and giant platelet (GP) counts reported by the DI-60 and the examiner exhibited strong correlations, they proved inadequate as effective indicators for screening samples containing PC. Between the PA and GP counts and four platelet indices (the platelet distribution width [PDW], mean platelet volume [MPV], platelet large cell ratio [P_LCR], and plateletcrit [PCT]) reported by the XN-9000, we observed statistically significant correlations (both overall and with group Y), but they were relatively weak. The platelet counts determined using the DI-60 and light microscopy in group Y showed substantial variations. Although the performance of the DI-60 was reliable for detecting PA and GP in smear images, such fixed areas are not representative of whole samples. Further, in the presence of PC, the resulting platelet counts determined using the DI-60 were not sufficiently accurate to be accepted as the final count.

FLI-1 is expressed in a wide variety of hematolymphoid neoplasms: a special concern in the differential diagnosis

Friend Leukemia Virus Integration 1 (FLI-1) is a member of E26 transformation-specific family of transcription factors that participates in hematopoietic and vascular endothelial cell development. Immunohistochemical detection of FLI-1 has been widely used to diagnose vascular tumors or, more evidently, Ewing's sarcoma. However, the expression pattern of FLI-1 in hematolymphoid neoplasms remains unclear. Therefore, in this study, we aimed to investigate the expression of FLI-1 in these tumors, focusing on high-grade lesions, which presents a diagnostic challenge by mimicking Ewing's sarcoma. We evaluated the expression FLI-1 in various types of lymphoid and plasmacytic tumors, including 27 plasmablastic lymphomas, 229 diffuse large B-cell lymphomas, 22 precursor T- or B-lymphoblastic lymphomas, 24 angioimmunoblastic-type nodal T-follicular helper cell lymphomas, 52 peripheral T-cell lymphomas, NOS, 18 Burkitt lymphomas, 18 non-gastric lymphomas of mucosa-associated lymphoid tissue, 38 chronic lymphocytic leukemia/small lymphocytic lymphomas, 15 mantle cell lymphomas, 23 gastric MALT lymphomas, 50 plasma cell myelomas, and 38 follicular lymphomas. We calculated the H-scores of FLI-1 immunostaining, ranging from 0 to 200, and used the scores to analyze the clinicopathological significance of FLI-1 statistically. FLI-1 was expressed to varying degrees in all types of hematological tumors. FLI-1 expression was detected in 84.1% of patients (466/554). FLI-1 was highly expressed in precursor T- or B-lymphoblastic lymphomas. Follicular lymphomas exhibited low FLI-1 expression. In plasmablastic lymphoma, 85.2% of the patients were focally positive for FLI-1. FLI-1 expression did not correlate with clinicopathological variables, such as demographic data or disease stage, in patients with plasmablastic lymphoma and diffuse large B-cell lymphoma. However, FLI-1 overexpression was associated with poorer overall survival in patients with plasmablastic lymphoma. This study demonstrates that FLI-1 is expressed in various hematolymphoid neoplasms. FLI-1 expression can lead to diagnostic confusion, especially in small blue round cell tumors, such as lymphoblastic lymphoma, plasmablastic lymphoma, and plasma cell myeloma, when distinguishing tumors positive for CD99 and CD56 without CD3, CD20, or CD45. Our findings also suggested the possibility of FLI-1 as a potential prognostic biomarker for plasmablastic lymphoma.

Is Bartonella sp. infection relevant in hematological malignancies in HIV-negative patients? A literature review

Bartonelloses are diseases caused by Bartonella sp., transmitted to humans by blood sucking arthropod vectors. Clinical presentations include bacillary angiomatosis, cat scratch disease and atypical forms. We performed a review of cases of bartonelloses and hematological malignancies published in HIV-negative patients. Terms used were Bartonella or Bacillary Angiomatosis and Leukemia, Lymphoma, Multiple Myeloma, or Cancer. Fifteen cases met our criteria. Clinical presentations included bacillary angiomatosis, chronic fever, chronic lymphadenopathy, osteomyelitis, neuroretinitis, chronic anemia and hepatosplenic peliosis. Fourteen patients were asymptomatic after antibiotic therapy, and one died before antibiotic treatment. Clinicians should be suspicious of Bartonella sp. infections in immunocompromised patients.

Frailty assessment to individualize treatment in older patients with lymphoma

PURPOSE

A study analyzing the application of a protocol of comprehensive geriatric assessment (CGA) in older patients with lymphoma was carried out to allow frailty-based patient classification and individualized treatment.

METHODS

Lymphoma patients older than 70 years referred to the Geriatric Clinic at a tertiary hospital between May 2016 and March 2021 were included. The assessment protocol included comorbidity, polypharmacy, nutritional, functional, and mental status, geriatric syndromes, and life expectancy. CGA enabled patient classification into four groups (Type I to Type IV) based on frailty assessment instrument scoring and clinical, functional, and mental status. Variables were compared using parametric and non-parametric statistical tests and Kaplan-Meier survival curves.

RESULTS

Ninety-three patients (55.9% women) were included. Median age was 81.1 years (± 5.7). 23 patients (24.7%) were classified as robust (type I), 30 (32.3%) as pre-frail (type II) with potentially reversable deficits, 38 (40.9%) as frail (type III), and 2 (2.2%) as requiring palliative care (type IV). Patients received oncospecific treatment with modifications carried out in 64.5% of cases based on CGA results. Differences in overall survival (p = 0.002), response to treatment (p < 0.001) and likelihood of increased frailty (p = 0.024) were observed, with type III-IV patients showing significantly worse outcomes.

CONCLUSION

Performance of standardized, systematic CGA by geriatricians permits older lymphoma patients to be classified according to frailty, with significant differences in terms of clinical outcomes across groups. We propose incorporating CGA performed by geriatricians as part of the multidisciplinary care team to optimize therapeutic strategy for these patients.

Intracranial hematolymphoid malignancies: A case series with molecular characterization

OBJECTIVE

Central nervous system (CNS) manifestations of hematologic malignancies are uncommon and often have a poor prognosis. As hematologic neoplasms are typically chemotherapy- and radiotherapy-sensitive, surgical resection is usually not indicated; thus, opportunities for in-depth characterization of CNS hematologic tumors are limited. Here, we report four cases of rare intracranial hematologic tumors requiring surgical intervention, allowing for histopathologic and genomic characterization.

METHODS

The clinical course, genetic perturbations, and histopathological features are described for a case of 1) primary marginal zone B-cell lymphoma of the dura as well as cases of brain metastases of 2) cutaneous T-cell lymphoma, 3) acute myeloid leukemia/myeloid sarcoma, and 4) multiple myeloma. Targeted DNA sequencing, fluorescence in situ hybridization, cytogenetic analysis, flow cytometry and immunohistochemical staining were used to assess the lesions.

RESULT

Molecular and histopathological characterizations of four unusual presentations of hematolymphoid diseases involving the CNS are presented. Genetic abnormalities were identified in each lesion, including chromosomal aberrations and single nucleotide variants resulting in missense or nonsense mutations in oncogenes.

CONCLUSIONS

Our case series provides insight into unique pathological phenotypes of hematologic neoplasms with atypical CNS involvement. We offer targets for future studies by identifying potentially pathogenic genetic variants in these lesions, as the full implications of the novel molecular abnormalities described remain unclear.

Risk of various cancers in adults with abdominal aortic aneurysms

BACKGROUND

The cause of death for patients with an abdominal aortic aneurysm (AAA) can be related to the AAA itself. However, cancer-related mortality could also be a contributing factor. In the present study, we examined the hypothesis that an association exists between AAAs and certain cancers.

METHODS

Information from 2009 to 2015 was extracted from the Korean National Health Insurance Service database. We included 14,920 participants with a new diagnosis of an AAA. Propensity score matching by age and sex with disease-free patients was used to select the control group of 44,760 participants. The primary end point of the present study was a new diagnosis of various cancers.

RESULTS

The hazard ratio (HR) for cancer incidence was higher in the AAA group than in the control group for hepatoma, pancreatic cancer, and lung cancer (HR, 1.376, 1.429, and 1.394, respectively). In the case of leukemia, the HR for cancer occurrence was not significantly higher in the AAA group than in the control group. However, when stratified by surgery, the HR was significantly higher for the surgical group (HR, 3.355), especially for endovascular aneurysm repair (HR, 3.864).

CONCLUSIONS

We found that AAAs are associated with an increased risk of cancer, in particular, hepatoma, pancreatic cancer, and lung cancer, even after adjusting for several comorbidities. Thus, continued follow-up is necessary for patients with an AAA to permit the early detection of the signs and symptoms of cancer.

Linking the Center for International Blood and Marrow Transplant Research Registry to the California Cancer Registry and California Hospital Patient Discharge Data

Advances in hematopoietic cell transplantation (HCT) have substantially improved patient survival, increasing the importance of studying outcomes and long-term adverse effects in the rapidly growing population of HCT survivors. Large-scale registry data from the Center for International Blood and Marrow Transplant Research (CIBMTR) are a valuable resource for studying mortality and late effects after HCT, providing detailed data reported by HCT centers on transplantation-related factors and key outcomes. This study was conducted to evaluate the robustness of CIBMTR outcome data and assess health-related outcomes and healthcare utilization among HCT recipients. We linked data from the CIBMTR for California residents with data from the population-based California Cancer Registry (CCR) and hospitalization information from the California Patient Discharge Database (PDD). In this retrospective cohort study, probabilistic and deterministic record linkage used key patient identifiers, such as Social Security number, ZIP code, sex, birth date, hematologic malignancy type and diagnosis date, and HCT type and date. Among 22,733 patients registered with the CIBMTR who underwent autologous or allogeneic HCT for hematologic malignancy between 1991 and 2016, 89.0% were matched to the CCR and/or PDD (n = 17,707 [77.9%] for both, n = 1179 [5.2%] for the CCR only, and n = 1342 [5.9%] for the PDD only). Unmatched patients were slightly more likely to have undergone a first autologous HCT than an allogeneic HCT (12.6% versus 9.0%), to have a larger number of missing linkage identifiers, and to have undergone HCT prior to 2010. Among the patients reported to the CIBMTR who matched to the CCR, 85.7% demonstrated concordance of both hematologic malignancy type and diagnosis date across data sources. This linkage presents unparalleled opportunities to advance our understanding of HCT practices and patient outcomes.

Extracorporeal membrane oxygenation in patients with hematologic malignancies: a systematic review and meta-analysis

Hematological malignancies (HM) have been, until recently, viewed as contraindications to extracorporeal membrane oxygenation (ECMO) due to bleeding and infectious complications. However, conflicting literature regarding whether ECMO should be used for patients with HM still exists. We conducted a random effects meta-analysis to investigate the outcomes of patients with HM on ECMO. We searched Medline, Embase, Scopus, and Cochrane through 10 October 2021. Risk of bias and certainty of evidence were assessed using the JBI checklists and GRADE approach respectively. Thirteen observational studies (422 patients with HM, 9778 controls without HM) were included. The pooled in-hospital mortality for patients with HM and those with hematopoietic stem cell transplants for HM indications needing ECMO were 79.1% (95%CI: 70.2-86.9%) and 87.7% (95%CI: 80.4-93.8%), respectively. Subgroup analyses found that mortality was higher in adults than children (85.1% vs 67.9%, p_interaction = 0.003), and in Asia compared to North America and Europe (93.8% vs 69.6%, p_interaction < 0.001). Pooled ECMO duration was 10.0 days (95%CI: 7.5-12.5); pooled ICU and hospital lengths of stay were 19.8 days (95%CI: 12.4-27.3) and 43.9 days (95%CI: 29.4-58.4) respectively. Age (regression coefficient [B]: 0.008, 95%CI: 0.003-0.014), proportion of males (B: 1.799, 95%CI: 0.079-3.519), and ECMO duration (B: - 0.022, 95%CI: - 0.043 to - 0.001) were significantly associated with higher mortality. In-hospital mortality of patients with HM who needed ECMO was 79.1%, with better outcomes in children, and in North America and Europe. ECMO should not be regarded as routine support therapy in these patients but can be carefully considered on a case-by-case basis.

Green tea consumption and risk of hematologic neoplasms: the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study)

PURPOSE

Experimental studies suggested that green tea may have an anticancer effect on hematologic neoplasms. However, few prospective studies have been conducted.

METHODS

A total of 65,042 individuals aged 40-79 years participated in this study and completed a self-administered questionnaire about their lifestyle and medical history at baseline (1988-1990). Of these, 52,462 individuals living in 24 communities with information on incident hematologic neoplasms available in the cancer registry, who did not have a history of cancer and provided valid information on frequency of green tea consumption, were followed through 2009. Hazard ratios (HRs) and 95% confidence intervals (CIs) for the incidence of hematologic neoplasms according to green tea consumption were analyzed.

RESULTS

The incidence of hematologic neoplasms during a median follow-up of 13.3 years was 323. Compared with the never-drinkers of green tea, the multivariate HRs and 95% CIs for total hematologic neoplasms in green tea drinkers of ≤ 2 cups/day, 3-4 cups/day, and ≥ 5 cups/day were 0.65 (0.42-1.00), 0.73 (0.47-1.13), and 0.63 (0.42-0.96), respectively. The association was more prominent for acute myeloid leukemias and follicular lymphomas.

CONCLUSIONS

The present cohort study suggests a protective effect of green tea against hematologic neoplasms, especially acute myeloid leukemias.

[Treatment of 30 elderly patients with advanced myeloid neoplasm by allogeneic hematopoietic stem cell transplantation]

Objective: To evaluate the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for elderly patients with advanced myeloid neoplasm. Methods: From September 2014 to September 2017, 30 consecutive hospitalized 50-plus-year-old myeloid neoplasm patients were retrospectively analyzed. At the time of transplantation, 6 patients reached complete remission and the others remained no remission after treatment. The donors were identical sibling (12), matched unrelated (6) and haploidentical family member (12), respectively. 18 patients received RIC while 12 patients received MAC conditioning regiments consisted of Busulfan, cytarabine, fludarabine or clarithromycin±TBI, respectively. Results: Five patients died early in the conditioning stage, 24 patients successfully engrafted. The median time of neutrophil engraftment was 14(10-18) d, whereas platelet engraftment was 15(10-19) d. Six cases (25%) experienced aGVHD grades Ⅱ, 8 cases (32%) cGVHD, including moderate to severe cGVHD in 2 cases (8%). Seven, 7 and 5 cases developed CMV viremia, pneumonia and herpeszoster, respectively after transplantation, but no patients died of infections. The median follow-up time of the patients was 7(0.5-38) months. Twenty-one patients were still alive. The estimated 2 years OS and LFS were 62.5% (95% CI 39.2%-85.8%) and 59.2% (95% CI 26.9%-91.5%), respectively. Univariate analysis showed that HCT-CI was the only factor influencing OS. Conclusion: Allogeneic hematopoietic stem cell transplantation could improve the survival of elderly patients with myeloid neoplasm.

Incidence of acute lymphocytic leukemia in Calgary, Alberta, Canada: a retrospective cohort study

Objective

Acute lymphocytic leukemia (ALL) is a rare malignant neoplasm that develops from abnormal lymphoid stem cells. ALL incidence is highest among children and declines towards adolescence. There is limited data on the epidemiology of ALL, especially in Canada. This retrospective cohort study used patient data from the Calgary Laboratory Services Cancer Cytogenetics Laboratory to report the incidence rate of ALL in Calgary, Alberta, Canada. New cases of ALL were identified for the 5-year period of January 1, 2011 until December 31, 2015. Reported incidence rates were categorized by sex and age groups, and age-standardized to the Canadian population.

Results

There were an average of 11.4 new cases of ALL diagnosed per year between 2011 and 2015. The total incidence rate per 100,000 person-years was 0.84. Incidence rates peaked in children aged 0–4 with 7.55 and 3.32 cases per 100,000 person-years for males and females, respectively. The median age of diagnosis was 8 years. Incidence rates were generally lowest for adults aged 20 and over. The ratio of males to females diagnosed with ALL was 1.59. Overall, the recent incidence of ALL in Calgary is comparatively low with a preference for males and children below 5 years of age.

Laboratory biomarkers for venous thromboembolism risk in patients with hematologic malignancies: A review. Thromb Res. 2018;163:138-145. [PMID: 29407626 DOI: 10.1016/j.thromres.2018.01.037]

INTRODUCTION

Despite high rates of venous thromboembolism (VTE) among patients with hematologic malignancies, few tools exist to assist providers in identifying those patients at highest risk for this potentially fatal complication. Laboratory biomarkers, such as d-dimer, have demonstrated utility in some clinical settings to distinguish patients at increased risk.

MATERIALS AND METHODS

We performed a systematic review of the literature utilizing search terms including "biomarker", "venous thromboembolism", "hematologic malignancy", "lymphoma", "myeloma" and "leukemia" in the Medline database. A total of 25 studies investigating laboratory biomarkers of increased thrombotic risk in the setting of hematologic malignancy were identified and included in this review.

RESULTS AND CONCLUSIONS

The most studied biomarkers, d-dimer and fibrinogen, demonstrated some degree of efficacy in identifying high-risk patients at levels >4.0 mg/L or <1.0 g/L respectively. Additional markers which demonstrated promise included thrombin generation, mean platelet volume, soluble VEGF, soluble P-selectin and extracellular vesicles. Other biomarkers reviewed, which did not consistently demonstrate significant associations with VTE included prothrombin fragments F1 + 2, factor VIII, protein C, protein S, von Willebrand antigen and activity, antithrombin, thrombin antithrombin complex, antiphospholopid antibody, plasminogen activator inhibitor, tissue factor pathway inhibitor and several variants associated with known hypercoagulable states (factor V Leiden, prothrombin gene variant, methylenetetrahydrofolate reductase variant). Data to support any of the biomarkers discussed here in routine clinical decision-making are currently lacking, but additional investigation in clinical studies, ideally in combination with clinical factors known to be associated with increased thrombotic risk, is warranted.

Epidemiology of venous thromboembolism in hematological cancers: The Scandinavian Thrombosis and Cancer (STAC) cohort

INTRODUCTION

Venous thromboembolism (VTE) is an important cause of morbidity and mortality in cancer patients, however the risk of VTE differs according to cancer type. Hematological cancers have varying phenotypes. Incidence rates (IR) of VTE in different hematological cancer types have not been investigated in a cancer-exposed subset of the general population.

METHODS

In a population-based cohort, we estimated incidence rates of VTE among patients with six subtypes of hematological cancer and among age and sex matched reference subjects.

RESULTS

During a mean follow-up of 4.8years, 30 objectively confirmed first-time symptomatic VTEs occurred among 838 subjects with hematological cancer. The IR of VTE was higher in all types of cancer except for indolent lymphoma but including chronic lymphocytic leukemia compared with reference subjects both during the first year after cancer diagnosis and 1-5years after diagnosis. IR of VTE for indolent lymphoma was not higher than controls.

CONCLUSION

The IRs of VTE were increased in all types of hematological cancer (including chronic lymphocytic leukemia) compared with reference subjects except indolent lymphomas.

Outcome and Clinical Significance of Immunophenotypic Markers Expressed in Different Treatment Protocols of Pediatric Patients With T-ALL in Developing Countries

BACKGROUND

T-cell acute lymphoblastic leukemia (T-ALL) accounts for about 15% of pediatric ALL. With wider use of intensive chemotherapy, the prognosis for childhood T-ALL has improved. Further gains in treatment outcome will likely require methods to identify patients who continue to fail on contemporary protocols. This study aimed to evaluate pediatric patients with T-ALL at 2 different Arabic cancer centers regarding their clinicopathologic, immunophenotypic, and cytogenetic features and outcome.

PATIENTS AND METHODS

This retrospective study included all children with T-ALL treated between 2003 and 2013 at 2 oncology centers in the Middle East. Patients were divided into (group I) treated with Berlin-Frankfurt-Münster (BFM)-90 treatment protocol between February 2003 and June 2007 and (group II) includes all patients treated thereafter by the Total Therapy Study XIII protocol for high-risk ALL.

RESULTS

This study included 103 patients with a median age of 8.9 years. The male to female ratio was 2.6:1. The median initial white blood cell count was 123 × 10⁹/L. Central nervous system leukemia was detected in 15%. The early T-cell precursor (ETP)-ALL phenotype was found in 16.5%. The 5-year overall survival was 20.7% ± 67.5% and 72.9% ± 5.7% (P < .01); the 5-year disease-free survival was 47.1% ± 13.8% and 77.3% ± 6.0% (P = .023); and the 5-year event-free survival was 28.6% ± 12.1% and 71.1% ± 6.2% (P = .003) for group I and II, respectively.

CONCLUSION

The outcome of patients with T-ALL significantly improved in patients who received the treatment protocol of ALL with high-risk criteria. This protocol eliminates the bad outcomes effect of several clinical and immunophenotypic markers. Patient with the ETP-ALL phenotype had a nonsignificant inferior outcome compared with the non-ETP-ALL group.

Comparison of two nutritional screening tools to detect nutritional risk in hematologic inpatients

OBJECTIVE

The aim of the study was to compare two nutritional screening tools in oncohematologic inpatients.

METHODS

A cross-sectional study was performed in a hematology ward from August to December 2015. Within the first 24 h of admission, the following nutritional screenings were performed: Malnutrition Universal Screening Tool (MUST), Malnutrition Screening Tool (MST), and Subjective Global Assessment (SGA). Patients who stayed in the hematologic ward were reevaluated with the three screening tools 1 and 2 wk after admission. The SGA was used as the gold standard in the detection of malnutrition.

RESULTS

Sixty-three patients were included in the study. Of these, 61.9% were men, ages 64 y (SD = 17.9 y) with 90.5% having a diagnosis of cancer. The prevalence of patients with nutritional risk at admission was 17.5% with SGA, 16.7% at week 1, and 31.6% at week 2. According to MST, the prevalence was 41.3% at admission, 13.9% at week 1, and 15.8% at week 2. According to MUST, the prevalence was 36.5%, 25%, and 36.8%, respectively. The results of diagnostic tests on admission were an area under the curve receiver operating characteristic of 0.691 for MST and 0.830 for MUST at admission; at week 1, 0.717 for MST and 0.850 for MUST; and at week 2 of assessment, 0.506 for MST and 0.840 for MUST.

CONCLUSION

MUST might be a better screening tool than MST for detecting the risk for malnutrition in oncohematological inpatients.

A case of multiple myeloma in a poultry worker

Background

Livestock breeders including poultry workers are exposed to various agricultural chemicals including pesticides and/or organic solvents. Multiple myeloma is a rare disease in Korea, and few reports have investigated the influence of occupational exposures on multiple myeloma occurrence.

Case presentation

A 61-year-old male poultry farm worker presented with bone pain and generalized weakness. A bone marrow biopsy was performed, and he was diagnosed with multiple myeloma. The patient had worked in a poultry farm for 16 years and was exposed to various pesticides and organic solvents such as formaldehyde without any proper personal protective equipment. Results of the work reenactment revealed that the concentration of formaldehyde (17.53 ppm) greatly exceeded the time-weighted average (0.5 ppm) and short-term exposure limit (1.0 ppm) suggested in the Korean Industrial Safety and Health Act.

Conclusions

This case report suggests that poultry workers may be exposed to high levels of various hazardous chemicals including pesticides and/or organic solvents. Numerous previous studies have suggested an association between multiple myeloma and exposure to agricultural chemicals; thus, multiple myeloma in this patient might have resulted from the prolonged, high exposure to these chemicals.

Electronic supplementary material

The online version of this article (doi:10.1186/s40557-014-0035-y) contains supplementary material, which is available to authorized users.

Molecular approach to diagnose BCR/ABL negative chronic myeloproliferative neoplasms

Chronic myeloproliferative neoplasms arise from clonal proliferation of hematopoietic stem cells. According to the World Health Organization myeloproliferative neoplasms are classified as: chronic myelogenous leukemia, polycythemia vera, essential thrombocythemia, primary myelofibrosis, chronic neutrophilic leukemia, chronic eosinophilic leukemia, hypereosinophilic syndrome, mast cell disease, and unclassifiable myeloproliferative neoplasms. In the revised 2008 WHO diagnostic criteria for myeloproliferative neoplasms, mutation screening for JAK2V617F is considered a major criterion for polycythemia vera diagnosis and also for essential thrombocythemia and primary myelofibrosis, the presence of this mutation represents a clonal marker. There are currently two hypotheses explaining the role of the JAK2V617F mutation in chronic myeloproliferative neoplasms. According to these theories, the mutation plays either a primary or secondary role in disease development. The discovery of the JAK2V617F mutation has been essential in understanding the genetic basis of chronic myeloproliferative neoplasms, providing some idea on how a single mutation can result in three different chronic myeloproliferative neoplasm phenotypes. But there are still some issues to be clarified. Thus, studies are still needed to determine specific molecular markers for each subtype of chronic myeloproliferative neoplasm.