Blastic Indeterminate Dendritic Cell Tumor Associated With Chronic Myelomonocytic Leukemia.

ABSTRACT: Indeterminate dendritic cell tumor (IDCT) is an exceedingly rare neoplasm that can be associated with hematopoietic malignancies. We report a case of multifocal cutaneous blastic indeterminate dendritic cell tumor (BIDCT) in a 75-year-old man with chronic myelomonocytic leukemia showing blastic histiocytoid morphology, positivity for CD1a and S100, and no expression of langerin. We present a literature review on the 11 reported cases of IDCTs/BIDCTs associated with chronic myelomonocytic leukemia (CMML), including this case. The clinicopathological characteristics have been summarized. The IDCT and CMML cells are clonally related in 4 tested cases. Patients with IDCT/BIDCT associated with CMML seem to have worse clinical outcomes compared with patients with IDCT not associated with CMML.

Large granular lymphocytic leukemia - A retrospective study of 319 cases.

Large granular lymphocytic leukemia (LGLL) is a rare hematological malignancy that arises from cytotoxic T lymphocytes (T-LGLL) in 85% of cases and natural killer (NK) cells in the rest. A significant knowledge gap exists regarding the pathogenesis, treatment choices, and prognostic factors of LGLL. We report a cohort of 319 consecutive LGLL patients who presented to our cancer center between 2001 and 2020. A total of 295 patients with T-LGLL and 24 with chronic NK-cell lymphoproliferative disorder (CLPD-NK) were identified. The median age was 65 years (range, 17-90 years). Eighty-three patients (26.0%) had autoimmune diseases. A total of 119 patients (37.3%) had coexisting malignancies, 66 (20.7%) had solid tumors, and 59 (18.5%) had hematological malignancies. Most coexisting malignancies were diagnosed before the diagnosis of LGLL. Treatment was needed for 57% of patients. Methotrexate (MTX), cyclophosphamide (Cy), and cyclosporine A (CSA) were most used and had similar response rates between 61.5%-74.4%. Cy produced more complete responses (32.3%) compared to MTX and CSA (15.7% and 23.1%, respectively). Thrombocytopenia, splenomegaly, and female gender (after controlling for autoimmune diseases) were associated with decreased response rates to MTX, CSA, or Cy. Autoimmune diseases were associated with increased response rates. Thrombocytopenia was an independent risk factor for worse survival.

Indeterminate dendritic cell neoplasm of the skin: A 2-case report and review of the literature.

Indeterminate dendritic cell neoplasm (IDCN) is an exceedingly rare and mostly cutaneous histiocytosis, frequently associated with other hematopoietic malignancies. We report 2 cases of multilesional cutaneous IDCN. A 55-year-old male with no associated malignancy and complete response to ultraviolet phototherapy; and a 72-year-old male with chronic myelomonocytic leukemia (CMML). Both cases showed histiocytoid cytology, positivity for CD1a and no expression of langerin or BRAFV600E . With our patients, the literature describes 79 cases of IDCNs, including 65 (82%) with only skin involvement, 7 cases (9%) with involvement of skin and a second site, 5 cases (6%) involving lymph nodes only, 1 splenic lesion and 1 systemic disease. Seventeen cases (22%) were associated with other hematopoietic malignancies, most commonly CMML (6 cases), follicular lymphoma (4 cases) and acute myeloid leukemia (3 cases). All IDCNs associated with myeloid malignancies were limited to the skin, while most cases associated with lymphoma were limited to lymph nodes. Reported responses of cutaneous lesions to ultraviolet phototherapy are encouraging, while systemic chemotherapy is appropriate for clinically aggressive cases and treatment of associated malignancies. Recognition of the clinico-morphologic spectrum of IDCNs should prevent misdiagnoses and prompt investigation of possible associated neoplasms.

Prognostic significance of soft tissue extension, international prognostic index, and multifocality in primary bone lymphoma: a single institutional experience.

Primary bone lymphoma (PBL) is a rare disease. The literature is inconsistent in regard to definition, stage and prognostic factors. We examined the PBL cases seen at the Moffitt Cancer Center between 1998 and 2013 using the 2013 World Health Organization criteria for bone/soft tissue tumours. Seventy PBL patients were included, of whom 53 (75.7%) patients were histologically classified as primary bone diffuse large B-cell lymphoma (PB-DLBCL). Femur was the most commonly involved site in PBLs with unifocal bone lesions, whereas PBLs with multifocal bone lesions most frequently presented with spine disease. Further analysis of the PB-DLBCL subgroup showed that these patients had 3- and 5-year progression-free survival (PFS) of 61.2% and 46.9%, respectively and 5- and 10-year overall survival (OS) of 81.1% and 74.7%, respectively. Multivariate analysis identified soft tissue extension and International Prognostic Index (IPI) score as the most important unfavourable prognostic factors for both PFS and OS. Multifocality was also highly significantly associated with a worse PFS (P = 0.002) and OS (P < 0.001), although it was not identified in multivariate analysis due to its incorporation into the IPI. The results warrant further investigation regarding whether PBL with multifocal bone lesions could be considered as a systemic and more aggressive disease rather than a conventional PBL.

Clinical characteristics and prognostic factors of bone lymphomas: focus on the clinical significance of multifocal bone involvement by primary bone large B-cell lymphomas.

BACKGROUND: Malignant bone lymphoma can be classified as primary (PBL) or secondary (SBL) bone lymphoma. However, the clinico-pathological characteristics and prognostic factors of PBL versus SBL have not yet been well defined. Whether lymphoma with multifocal bone involvement should be considered as stage IV PBL or SBL still remain controversial throughout the literature. METHODS: In this study, we retrospectively reviewed 127 patients with bone lymphoma diagnosed from 1998 to 2013 at the Moffitt Cancer Center. Patients were classified as PBL (81 cases) and SBL (46 cases) using the 2013 WHO Classification of Bone/Soft Tissue Tumors and PBL patients were further subdivided into: 1) PBL with unifocal bone disease (uPBL, 46 cases), 2) PBL with multifocal bone involvement (mPBL, 35 cases). Patient characteristics, survival, and prognostic factors were analyzed. RESULTS: Diffuse large B-cell lymphoma (DLBCL) was the most common histological subtype in all three groups (37/46 of uPBL, 23/35 of mPBL, 23/46 of SBL). B symptoms, lymph node involvement, and bone marrow involvement were found to be more common in mPB-DLBCL and SB-DLBCL groups than in the uPB-DLBCL group. Femur was found to be the most common affected site in uPB-DLBCL patients, while spine was most commonly involved in the other two groups. Survival analysis indicated that uPBL-DLBCL patients had a significantly better progression-free survival (PFS) and overall survival (OS) than those in the other two groups (P<0.05). We also found by univariate analysis that multifocality, and stage IV were significantly poor prognostic factors for both PFS and OS in PBL patients. Using multivariate analysis, multifocality remained an independent prognostic factor for both PFS and OS (P=0.0117, RR: 3.789, 95% CI: 1.275-11.256). CONCLUSION: Overall, our results suggest that mPBL is more similar to SBL in characteristics and survival rather than uPBL, and thus should be better classified and treated as SBL.

Dendritic cell and histiocytic neoplasms: biology, diagnosis, and treatment.

BACKGROUND: Dendritic and histiocytic cell neoplasms are rare malignancies that make up less than 1% of all neoplasms arising in lymph nodes or soft tissues. These disorders have distinctive disease biology, clinical presentations, pathology, and unique treatment options. Morphology and immunohistochemistry evaluation by a hematopathologist remains key for differentiating between these neoplasms. In this review, we describe tumor biology, clinical features, pathology, and treatment of follicular dendritic cell sarcoma, interdigitating dendritic cell sarcoma, indeterminate dendritic cell sarcoma, histiocytic sarcoma, fibroblastic reticular cell tumors, and disseminated juvenile xanthogranuloma. METHODS: A literature search for articles published between 1990 and 2013 was undertaken. Articles are reviewed and salient findings are systematically described. RESULTS: Patients with dendritic cell and histiocytic neoplasms have distinct but variable clinical presentations; however, because many tumors have recently been recognized, their true incidence is uncertain. Although the clinical features can present in many organs, most occur in the lymph nodes or skin. Most cases are unifocal and solitary presentations have good prognoses with surgical resection. The role of adjuvant therapy in these disorders remains unclear. In cases with disseminated disease, prognosis is poor and data on treatment options are limited, although chemotherapy and referral to a tertiary care center should be considered. Excisional biopsy is the preferred method of specimen collection for tissue diagnosis, and immunohistochemistry is the most important diagnostic method for differentiating these disorders from other entities. CONCLUSIONS: Dendritic cell and histiocytic cell neoplasms are rare hematological disorders with variable clinical presentations and prognoses. Immunohistochemistry remains important for diagnosis. Larger pooled analyses or clinical trials are needed to better understand optimal treatment options in these rare disorders. Whenever possible, patients should be referred to a tertiary care center for disease management.

Cutaneous gamma-delta T-cell lymphoma with central nervous system involvement: report of a rarity with review of literature.

Primary cutaneous gamma-delta (γδ) T-cell lymphoma is an extremely rare and aggressive variant of cutaneous lymphoma. Central nervous system (CNS) involvement, a rare finding, and hemophagocytic syndrome are two complications that are commonly fatal. We describe a 58-year-old patient presenting with skin plaque who subsequently developed subcutaneous nodules diagnosed as cutaneous T-cell lymphoma (CTCL), clinically resembling 'mycosis fungoides'. The patient was treated with repeat topical radiation therapies but had frequent relapsed disease. Approximately 4.5 years after, the patient presented with third and sixth cranial nerve palsies and was found to have CNS involvement by lymphoma per positron emission tomography-computed tomography (PET/CT) and a biopsy of foramen magnum. Phenotypically, the tumor cells were CD3(+)/CD4(-)/CD8(-)/CD7(+)/CD5(-)/CD30(-)/TCRαß(-)/TCRγδ(+). Despite aggressive strategies taken, the patient expired 3 months after the diagnosis of the CNS lesion. A retrospective investigation proved the original CTCL to be γδ T-cell in origin, confirming an indolent cutaneous γδ T-cell lymphoma with eventual CNS manifestation. We present this case to draw attention to the entity, which can occasionally present with misleading histopathologic and clinical features. In addition, we provide a review of the literature to summarize clinical and pathologic features of the reported similar cases.

The monitoring requests on young driver's fatigue and take-over performance in prolonged conditional automated driving.

INTRODUCTION: L3 automated vehicles can perform all dynamic driving tasks unless a take-over occurs due to operational limits. This issue is potentially important for young drivers who are vulnerable road users since they have skill deficits and easily evolve into aberrant driving. However, drivers lacking active involvement may be fatigued and drowsy. Previous research indicated that performing a voluntary non-driving-related task (NDRT) could keep drivers alert, but there was no difference in take-over performance with or without NDRT. Providing a monitoring request (MR) before a possible take-over request (TOR) exhibited better take-over performance in temporary automated driving. Therefore, the study aimed to investigate the effects of MR and voluntary NDRT on young drivers' fatigue and performance. METHOD: Twenty-five young drivers experienced 60 min automated driving on a highway with low traffic density and a TOR prompted due to a collision event. A within-subjects was designed that comprised three conditions: NONE, TOR-only, and MR + TOR. Drivers were allowed to perform a self-paced phone NDRT during automated driving. RESULTS: The PERCLOS and blink frequency data showed that playing phones could keep drivers vigilant. The take-over performance on whether taking phone had no difference, but with MRs condition exhibited better take-over performance including the shorter reaction time and the longer TTC. Subjective evaluations also showed the advantages of MRs with more safety, trust, acceptance, and lower workload. CONCLUSIONS: Taking MRs had a positive effect on relieving fatigue and improving take-over performance. Furthermore, MRs could potentially improve the safety and acceptance of automated driving. PRACTICAL APPLICATIONS: The MR design can be used in the automotive industry to ensure the safest interfaces between fatigue drivers and automation systems.

Primary cutaneous CD4 positive small/medium T-cell lymphoma with high proliferation index and CD30-positive large lymphoid cells.

Primary cutaneous CD4 positive small/medium pleomorphic T-cell lymphoma (SMPTCL) represents a provisional subtype of primary cutaneous T-cell lymphoma with indolent clinical course. A few aggressive fatal cases with increased proliferation rate and few infiltrating CD8 positive T-cells have been reported. We describe a case of SMPTCL with an increased proliferation rate, admixed CD30-positive large lymphoid cells, and few infiltrating CD8 positive T-cells. The lymphoma cells were positive for CD3, CD4, CD2 and CD5, and negative for CD8. A subset of the lymphoma cells was positive for follicular helper T-cell markers bcl-6 and PD-1. There were approximately 20% CD30-positive large lymphoid cells, and Ki-67 showed a moderately high proliferation rate (~40%), mostly in the large lymphoid cells. CD8 infiltrating T-cells were few (<5%). The patient had an indolent disease with complete response to radiation therapy. To the best of our knowledge, this is the first reported case of SMPTCL with an increased proliferation rate and large CD30+ cells that followed an indolent clinical course.

Co-mutation of ASXL1 and SF3B1 Predicts Poorer Overall Survival Than Isolated ASXL1 or SF3B1 Mutations.

BACKGROUND/AIM: Mutations in the ASXL transcriptional regulator 1 (ASXL1) and splicing factor 3b subunit 1(SF3B1) genes are commonly observed in myeloid neoplasms and are independent predicative factors for overall survival (OS). Only a few contradictory reports exist on the clinical significance of concurrent ASXL1 and SF3B1 mutations. Previous studies also did not exclude patients with mutations of other genes, which could be confounding factors. MATERIALS AND METHODS: We identified 69 patients with mutation of only ASXL1, 89 patients with mutation of only SF3B1, and 17 patients with mutations exclusively of both ASXL1 and SF3B1 from our database of 8,285 patients and compared their clinical features and outcomes. RESULTS: Patients with ASXL1 mutations more frequently had acute myeloid leukemia (22.47%) or clonal cytopenia of unknown significance than patients with SF3B1 mutations (1.45%) or with ASXL1/SF3B1 mutations (11.76%). Patients with SF3B1 or ASXL1/SF3B1 mutations were more frequently diagnosed with myelodysplastic syndrome (75.36% and 64.71%, respectively) than patients with ASXL1 mutations (24.72%). Patients with ASXL1/SF3B1 (23.53%) mutations more frequently had myelodysplastic/myeloid proliferative neoplasm than did patients with ASXL1 mutations (5.62%) or with SF3B1 mutations (15.94%). OS of the ASXL1 mutation-only group was worse than that of the SF3B1 mutation-only group with a hazard ratio of 5.83 (p=0.017). Finally, and most importantly, the OS of the ASXL1/SF3B1 co-mutation group was poorer than that of both single-mutation groups (p=0.005). CONCLUSION: ASXL1/SF3B1 co-mutations portend worse OS than isolated ASXL1 or SF3B1 mutations, which might be due to abnormalities in both the epigenetic-regulatory and RNA-splicing pathways or because two genes instead of one are mutated.

Clonally related histiocytic/dendritic cell sarcoma and chronic lymphocytic leukemia/small lymphocytic lymphoma: a study of seven cases.

Histiocytic and interdigitating dendritic cell sarcomas are rare tumors originating from bone marrow-derived myeloid stem cells. Recent studies have shown evidence of cross-lineage transdifferentiation of B cells in follicular lymphoma to histiocytic and dendritic cell sarcomas. In this study, we report the morphologic, molecular and cytogenetic analysis of seven cases of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) associated with histiocytic and dendritic cell sarcomas. All seven patients were elderly males (median age 71 years). The B-cell neoplasms preceded the development of the histiocytic and dendritic cell sarcomas in six of seven patients, and one patient had both tumors diagnosed at the same time. The tumors included four interdigitating dendritic cell sarcomas: one Langerhans cell sarcoma, one histiocytic sarcoma and one immature neoplasm with evidence of histiocytic origin. Laser-capture microdissection and PCR analysis showed identical clonal immunoglobulin gene rearrangements in the two phenotypically distinct components in all cases. There was a preferential usage of IGHV4-39 by the V-D-J gene rearrangement. By fluorescence in situ hybridization (FISH) analysis, two cases showed deletion 17p in both components, whereas four cases had normal cytogenetic findings by FISH in the CLL/SLL cells, but acquired cytogenetic abnormalities in the corresponding histiocytic and dendritic tumors. Chromosome 17p abnormalities were the most common cytogenetic abnormality detected in the sarcomas, seen in five of six cases studied. Compared with the CLL/SLL cells, the histiocytic/dendritic cells were largely negative for PAX5, but showed strong expression of PU.1 and variable and weak expression of CEBPß. Our study provides evidence for transdifferentiation of CLL/SLL B cells to tumors of dendritic and less often histiocytic lineage, and suggests that secondary genetic events may play a role in this phenomenon.

Insights into Factors Affecting Traffic Accident Severity of Novice and Experienced Drivers: A Machine Learning Approach.

Traffic accidents have significant financial and social impacts. Reducing the losses caused by traffic accidents has always been one of the most important issues. This paper presents an effort to investigate the factors affecting the accident severity of drivers with different driving experience. Special focus was placed on the combined effect of driving experience and age. Based on our dataset (traffic accidents that occurred between 2005 and 2021 in Shaanxi, China), CatBoost model was applied to deal with categorical feature, and SHAP (Shapley Additive exPlanations) model was used to interpret the output. Results show that accident cause, age, visibility, light condition, season, road alignment, and terrain are the key factors affecting accident severity for both novice and experienced drivers. Age has the opposite impact on fatal accident for novice and experienced drivers. Novice drivers younger than 30 or older than 55 are prone to suffer fatal accident, but for experienced drivers, the risk of fatal accident decreases when they are young and increases when they are old. These findings fill the research gap of the combined effect of driving experience and age on accident severity. Meanwhile, it can provide useful insights for practitioners to improve traffic safety for novice and experienced drivers.

Myeloid/lymphoid neoplasms with eosinophilia and FLT3 rearrangement.

Myeloid/lymphoid neoplasms with eosinophilia and gene rearrangement are a unique category in the WHO classification, and include cases with rearrangement of PDGFRA, PDGFRB, FGFR1, and PCM1-JAK2. We report three patients presented with eosinophilia and FLT3 rearrangement: the first case with chronic eosinophilic leukemia, not otherwise specified and T-lymphoblastic leukemia/lymphoma; the second case with myeloid sarcoma; and the last case with high-grade myelodysplastic syndrome. The first case showed t(13;14)(q12;q32), which encoded FLT3-TRIP11. The patient was treated with intense chemotherapy and subsequently sorafenib with clinical improvement. Unfortunately, the patient showed persistent residual disease and passed away 9 months after the diagnosis from pneumonia. The other two cases both showed ETV6-FLT3. The second patient was treated with local radiation and systemic chemotherapy including sorafenib and was alive. The third patient was treated with chemotherapy but showed transformation to acute myeloid leukemia and died 15 months after diagnosis. These cases are among a growing number of cases with FLT3 rearrangement that all showed similar clinicopathologic features characterized by myeloproliferative neoplasm with eosinophilia and frequent T lymphoblastic leukemia/lymphoma. Therefore, we propose that the myeloid/lymphoid neoplasms with eosinophilia and FLT3 rearrangement be included in the WHO category of myeloid/lymphoid neoplasms with eosinophilia and gene rearrangement.

Comparison of SF3B1/DNMT3A Comutations With DNMT3A or SF3B1 Mutation Alone in Myelodysplastic Syndrome and Clonal Cytopenia of Undetermined Significance.

OBJECTIVES: To compare the clinical significance of SF3B1/DNMT3A Comutations with SF3B1 or DNMT3A mutation alone in myelodysplastic syndrome (MDS) and clonal cytopenia of undetermined significance (CCUS). METHODS: We identified and compared 31 patients with only DNMT3A mutation, 48 patients with only SF3B1 mutation, and 16 patients with only SF3B1/DNMT3A comutations. RESULTS: SF3B1/DNMT3A comutations were found to be more common in MDS, whereas DNMT3A mutation alone was more common in CCUS. The patients with SF3B1/DNMT3A comutations were less likely to have poor cytogenetics than patients with DNMT3A mutation alone. Patients with SF3B1/DNMT3A comutations showed significantly longer median survival time and better overall survival than patients with DNMT3A mutation alone. CONCLUSIONS: Patients with SF3B1/DNMT3A comutations appear to have better clinical outcomes than patients with isolated DNMT3A mutation. These findings suggest that the favorable prognosis of SF3B1 mutation in is not abrogated by the concurrent presence of a DNMT3A mutation.

Naïve/memory T-cell phenotypes in leukemic cutaneous T-cell lymphoma: Putative cell of origin overlaps disease classification.

BACKGROUND: Mycosis fungoides (MF) and Sézary Syndrome (SS) are clinically distinct cutaneous T-cell lymphomas with strikingly similar morphologic and phenotypic features. Prior studies have suggested phenotypic differences based on markers of antigen experience, suggesting a different cell of origin. METHODS: Seventy-nine involved peripheral blood or bone marrow samples from 33 patients with SS and 19 patients with MF were studied by 10-color flow cytometry, including CD62L, CD45RA, CCR4, and PD-1. Gated tumor events were classified as naïve (TN ), central memory (TCM ), effector memory (TEM ), or effector memory with reacquired CD45RA (TEMRA ); based on CD62L+ /CD45RA+ , CD62L+ /CD45RA- , CD62L- /CD45RA- , or CD62L- /CD45RA+ phenotype, respectively. Sequential specimens were compared to assess for phenotypic stability. RESULTS: The naïve/memory phenotype of the neoplastic T-cells was markedly heterogeneous, with a dominant TN , TCM , TEM , or TEMRA subset on 11 (14%), 32 (41%), 30 (38%), and 6 (8%) cases, respectively. There was no correlation between the diagnosis of MF or SS and putative cell of origin (P = 0.4). Overexpression of CCR4 and PD1 was observed in most cases, with higher intensity in SS compared to MF. The naïve/memory phenotype remained the same for 10 patients up to 273 days after the initial analysis; while on six patients, the naïve/memory phenotype was different from the original phenotype. CONCLUSIONS: Both SS and MF can have phenotypic features of any of the major naïve/memory T-cell subsets, which questions the current principle of "cell-of-origin" distinction between SS and MF. Phenotypic shifts within these subsets are common, suggesting a functional state rather than a cell-of-origin surrogate. © 2018 International Clinical Cytometry Society.

Transformation of T-Cell Acute Lymphoblastic Lymphoma to Peripheral T-Cell Lymphoma: A Report of Two Cases.

Nonhepatosplenic/noncutaneous γδ peripheral T-cell lymphoma (NHNCγδ PTCL) represents a miscellaneous group of unrelated T-cell lymphomas of which only isolated cases have been reported. We describe two cases of transformation from T-lymphoblastic leukemia/lymphoma to NHNCγδ PTCL. Transformation into more aggressive disease is a rare event in T-cell lineage-derived hematologic malignancies compared to B-cell neoplasms. Nevertheless, both of our cases involved relapse as PTCL manifested with skin involvement and an overt shift from blastic morphology to large granular leukemia-like mature T cells. Among other notable molecular characteristics, expression of immature markers such as TdT was lost in both cases. Based on cytogenetics, phenotype, and morphology, both patients represent a novel phenomenon of clonal transformation from T-ALL to PTCL which has rarely been reported in the literature. Such transformation may carry important diagnostic and biological implications.

The Role of c-MYC in B-Cell Lymphomas: Diagnostic and Molecular Aspects.

c-MYC is one of the most essential transcriptional factors, regulating a diverse array of cellular functions, including proliferation, growth, and apoptosis. Dysregulation of c-MYC is essential in the pathogenesis of a number of B-cell lymphomas, but is rarely reported in T-cell lymphomas. c-MYC dysregulation induces lymphomagenesis by loss of the tight control of c-MYC expression, leading to overexpression of intact c-MYC protein, in contrast to the somatic mutations or fusion proteins seen in many other oncogenes. Dysregulation of c-MYC in B-cell lymphomas occurs either as a primary event in Burkitt lymphoma, or secondarily in aggressive lymphomas such as diffuse large B-cell lymphoma, plasmablastic lymphoma, mantle cell lymphoma, or double-hit lymphoma. Secondary c-MYC changes include gene translocation and gene amplification, occurring against a background of complex karyotype, and most often confer aggressive clinical behavior, as evidenced in the double-hit lymphomas. In low-grade B-cell lymphomas, acquisition of c-MYC rearrangement usually results in transformation into highly aggressive lymphomas, with some exceptions. In this review, we discuss the role that c-MYC plays in the pathogenesis of B-cell lymphomas, the molecular alterations that lead to c-MYC dysregulation, and their effect on prognosis and diagnosis in specific types of B-cell lymphoma.

Comparison of the Mutational Profiles of Primary Myelofibrosis, Polycythemia Vera, and Essential Thrombocytosis.

OBJECTIVES: To compare the mutational profiles of patients with primary myelofibrosis (PMF), polycythemia vera (PV), and essential thrombocytosis (ET). METHODS: Next-generation sequencing results of 75 cases of PMF, 33 cases of PV, and 27 cases of ET were compared. RESULTS: Mutation rates of ASXL1 and SRSF2 were significantly higher in PMF than in PV or ET. ASXL1 mutations appeared to be more frequently associated with risk of transformation to acute myeloid leukemia than JAK2 or TET2 mutations. The most common mutation-cytogenetic combinations in myeloproliferative neoplasm (MPN) were mutations of JAK2 or ASXL1 with del(20q) and were more common in patients with PMF and PV than in patients with ET. Differences were also found between patients with PMF and PV. CONCLUSIONS: PMF, PV, and ET show different mutational profiles, which may be helpful in resolving the differential diagnosis between MPNs. Due to the relatively small number of cases and variable testing over time, larger controlled studies are necessary to confirm the findings.

SNP Array in Hematopoietic Neoplasms: A Review.

Cytogenetic analysis is essential for the diagnosis and prognosis of hematopoietic neoplasms in current clinical practice. Many hematopoietic malignancies are characterized by structural chromosomal abnormalities such as specific translocations, inversions, deletions and/or numerical abnormalities that can be identified by karyotype analysis or fluorescence in situ hybridization (FISH) studies. Single nucleotide polymorphism (SNP) arrays offer high-resolution identification of copy number variants (CNVs) and acquired copy-neutral loss of heterozygosity (LOH)/uniparental disomy (UPD) that are usually not identifiable by conventional cytogenetic analysis and FISH studies. As a result, SNP arrays have been increasingly applied to hematopoietic neoplasms to search for clinically-significant genetic abnormalities. A large numbers of CNVs and UPDs have been identified in a variety of hematopoietic neoplasms. CNVs detected by SNP array in some hematopoietic neoplasms are of prognostic significance. A few specific genes in the affected regions have been implicated in the pathogenesis and may be the targets for specific therapeutic agents in the future. In this review, we summarize the current findings of application of SNP arrays in a variety of hematopoietic malignancies with an emphasis on the clinically significant genetic variants.