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Introduction: The mechanism of relapsed CD19(−) B‐ALL after anti‐CD19 immunotherapy (Kymriah [CART‐19] and blinatumomab) is under active investigation. Our study aims to assess LILRB1 as a novel B‐cell marker for detecting CD19(−) B‐lymphoblasts and to analyze the clinicopathologic/genetic features of such disease to provide biological insight into relapse. Methods: Six patients (3 males/3 females, median age of 14 years) with relapsed CD19(−) B‐ALL were analyzed for cytogenetic/genetic profile and immunophenotype. Results: CD19(−) B‐ALL emerged after an interval of 5.8 months following anti‐CD19 therapy. Five of six patients had B‐cell aplasia, indicative of a persistent effect of CART or blinatumomab at relapse. Importantly, LILRB1 was variably expressed on CD19(−) and CD19(+) B lymphoblasts, strong on CD34(+) lymphoblasts and dim/partial on CD34(−) lymphoblasts. Three of six patients with paired B‐ALL samples (pre‐ and post‐anti‐CD19 therapy) carried complex and different cytogenetic abnormalities, either as completely different or sharing a subset of cytogenetic abnormalities. Conclusion: LILRB1 can be used as a novel B‐cell marker to identify CD19(−) B lymphoblasts. The emergence of CD19(−) B‐ALL appears to be associated with complex cytogenetic evolutions. The mechanism of CD19(−) B‐ALL relapse under anti‐CD19 immune pressure remains to be explored by comprehensive molecular studies. [ABSTRACT FROM AUTHOR]

Philadelphia (BCR- ABL)- negative myeloproliferative neoplasms (MPNs) include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). MPN can transform into an accelerated or a blast phase, which is associated with poor response to standard therapy and low overall median survival. We present an interesting case of a patient with a history of PMF and progression and summarize the current studies on genetic features of myeloproliferative neoplasms in blast phase (MPN- BP) with an emphasis on PMF. Although MPN- BP show ≥20% blasts in peripheral blood or bone marrow, it is not considered as acute myeloid leukemia (AML) according to the WHO classification. While MPNs- BP typically lack genetic mutations seen in de novo AML, they commonly harbor IDH1/2, SRSF2, ASXL1, and TP53 mutations, similar to the genetic profiles of acute myeloid leukemia with myelodysplasia-related changes (AML- MRC). [ABSTRACT FROM AUTHOR]

Philadelphia (BCR‐ABL)‐negative myeloproliferative neoplasms (MPNs) include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). MPN can transform into an accelerated or a blast phase, which is associated with poor response to standard therapy and low overall median survival. We present an interesting case of a patient with a history of PMF and progression and summarize the current studies on genetic features of myeloproliferative neoplasms in blast phase (MPN‐BP) with an emphasis on PMF. Although MPN‐BP show ≥20% blasts in peripheral blood or bone marrow, it is not considered as acute myeloid leukemia (AML) according to the WHO classification. While MPNs‐BP typically lack genetic mutations seen in de novo AML, they commonly harbor IDH1/2, SRSF2, ASXL1, and TP53 mutations, similar to the genetic profiles of acute myeloid leukemia with myelodysplasia‐related changes (AML‐MRC). [ABSTRACT FROM AUTHOR]

Summary T/myeloid mixed phenotype acute leukaemia (MPAL) is a rare aggressive acute leukaemia with poorly understood pathogenesis. Herein, we report two cases of T/myeloid MPAL harbouring BCL11B‐associated structural variants that activate TLX3 (TLX3::BCL11B‐TLX3‐activation) by genome sequencing and transcriptomic analyses. Both patients were young males with extramedullary involvement. Cooperative gene alterations characteristic of T/myeloid MPAL and T‐lymphoblastic leukaemia (T‐ALL) were detected. Both patients achieved initial remission following lineage‐matched ALL‐based therapy with one patient requiring a lineage‐switched myeloid‐based therapy. Our study is the first to demonstrate the clinicopathological and genomic features of TLX3::BCL11B‐TLX3‐activated T/myeloid MPAL and provide insights into leukaemogenesis. [ABSTRACT FROM AUTHOR]

Background: Fluorescence labeled DNA probes and in situ hybridization methods had shorter turn round time for results revolutionized their clinical application. Signals obtained from these probes are highly specific, yet they can produce fusion signals not necessarily representing fusion of actual genes due to other genes included in the probe design. In this study we evaluated discordance between cytogenetic, FISH and RNAseq results in 3 different patients with hematologic malignancies and illustrated the need to perform next generation sequencing (NGS) or RNASeq to accurately interpret FISH results. Methods: Bone marrow or peripheral blood karyotypes and FISH were performed to detect recurring translocations associated with hematologic malignancies in clinical samples routinely referred to our clinical cytogenetics laboratory. When required, NGS was performed on DNA and RNA libraries to detect somatic alterations and gene fusions in some of these specimens. Discordance in results between these methods is further evaluated. Results: For a patient with plasma cell leukemia standard FGFR3 / IGH dual fusion FISH assay detected fusion that was interpreted as FGFR3 -positive leukemia, whereas NGS/RNASeq detected NSD2::IGH. For a pediatric acute lymphoblastic leukemia patient, a genetic diagnosis of PDGFRB -positive ALL was rendered because the PDGFRB break-apart probe detected clonal rearrangement, whereas NGS detected MEF2D::CSF1R. A MYC -positive B-prolymphocytic leukemia was rendered for another patient with a cytogenetically identified t(8;14) and MYC::IGH by FISH, whereas NGS detected a novel PVT1::RCOR1 not previously reported. Conclusions: These are 3 cases in a series of several other concordant results, nevertheless, elucidate limitations when interpreting FISH results in clinical applications, particularly when other genes are included in probe design. In addition, when the observed FISH signals are atypical, this study illustrates the necessity to perform complementary laboratory assays, such as NGS and/or RNASeq, to accurately identify fusion genes in tumorigenic translocations. [ABSTRACT FROM AUTHOR]

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B-cell maturation from hematogones to mature B cells in bone marrow exhibits a consistent, complex spectrum of sequential antigen expression. CD5 expression, however, has not been characterized. We studied the dynamics of CD5 expression on developing B cells by 4-color flow cytometry in 32 patients, aged 9 months to 63 years, with hematogone hyperplasia (>3.5% of total events). The mean percentage of hematogones was 8.1%. We demonstrate consistent CD5 expression on normal, polytypic B cells in a continuum, predominantly at later stages of maturation, specifically on stage 3 hematogones and mature B cells. Awareness of this normal pattern of CD5 expression on B-cell subsets has implications in the analysis of minimal residual disease of CD5 B-lineage non-Hodgkin lymphomas. [ABSTRACT FROM AUTHOR]

An association between intravascular large B-cell lymphoma (IVLBCL) and the mixed lineage leukemia (MLL) gene has never been demonstrated. Here, we report an IVLBCL in a 47-year-old Asian man. Morphologically, the atypical lymphoid infiltrate was entirely confined in the lumina of capillaries, small vessels, and sinusoidal space. Within the kidney, the neoplastic lymphoid cells exhibited both the glomerular and peritubular capillary distribution pattern. Conventional cytogenetic analysis from the bone marrow aspirates displayed a complex karyotype, with a notable triple tandem repeat at band segment q22–q25 of chromosome 11. Fluorescence in situ hybridization with an MLL probe set, performed on both interphase cells and metaphase spreads, confirmed the presence of 3 copies of the MLL gene on the derivative chromosome 11. From this finding and 3 other IVLBCL cases reported in the literature, we conclude that MLL may play an important role in the lymphomagenesis of IVLBCL at least in a subset of cases. [ABSTRACT FROM AUTHOR]

Abstract: Background: Plasma acylcarnitine measurement is an important diagnostic tool for inherited disorders of fatty acid and organic acid metabolism. Biliary excretion has been shown to be the primary route of excretion for acylcarnitines and analysis of bile acylcarnitine profiles may provide greater sensitivity for detecting metabolic disorders. Disorders of fatty acid oxidation frequently present with deranged liver function and the effect of hepatic disease on biliary acylcarnitine excretion are unknown. Methods: We measured biliary acylcarnitine levels in pediatric patients aged 6 months to 1 year undergoing open liver biopsy with prospectively determined non-metabolic liver disease in order to determine the effect of the liver disease on acylcarnitine excretion. Bile was collected in syringes and was transported immediately and stored at −70 °C until the time of testing. The disease patient population consisted of 2 patients with known defects in long- and short-chain fatty acid oxidation (long-chain L-3-hydroxy acyl-CoA dehydrogenase: LCHAD and short-chain L-3-hydroxy acyl-CoA dehydrogenase: SCHAD). The sample from the LCHAD patient was collected at autopsy and the patient with SCHAD deficiency was subsequently diagnosed as part of the prospective study and removed from the unknown etiology group. Acylcarnitine profiles were obtained for each specimen as butylated derivatives using tandem mass spectrometry. Results: The non-metabolic liver disease had no effect on the diagnostic value of bile acylcarnitine levels for detecting LCHAD deficiency. The concentrations of bile long-chain acylcarnitine species analyzed from patients with non-metabolic liver disease were far lower than the levels seen in LCHAD deficiency which also demonstrated a characteristic pattern of 3-hydroxyacylcarnitine excretion. In SCHAD deficiency, for which pathognomonic markers have not yet been established, bile analysis did not improve the diagnostic ability. Conclusion: The analysis of bile acylcarnitines for the diagnosis of long-chain fatty acid oxidation defects will provide unbiased information even in the presence of severe non-metabolic liver disease. [Copyright &y& Elsevier]

Objectives: Diagnosis of high-grade B-cell lymphoma with MYC and BCL2 or BCL6 rearrangements (double-/triple-hit lymphoma [DTHL]) appears to mandate fluorescence in situ hybridization (FISH) testing for all large B-cell lymphoma (LBCL). Given the low incidence of DTHL, we aimed to identify flow cytometry (FC) and immunohistochemistry (IHC) features of DTHL that could be used to develop an optimal screening strategy. This combined FC-IHC approach has not yet been studied.Methods: We compared features of 40 cases of DTHL and 39 cases of diffuse LBCL (DLBCL) without MYC rearrangement.Results: Bright CD38 expression (CD38bright) by FC, high MYC expression (≥55%), and double-expressor phenotype by IHC were significantly associated with DTHL. The biomarker combining FC and IHC, CD38bright and/or MYC ≥55%, was superior to FC and IHC markers alone in predicting DTHL. Restricting FISH testing to approximately 25% of LBCL based on CD38brightand/or MYC ≥55% would detect approximately 95% of DTHL-BCL2 and approximately 75% of DHL-BCL6.Conclusions: Our study demonstrated that the novel biomarker of CD38bright and/or MYC ≥55% is highly predictive of DTHL. Awareness of the advantages and limitations of this screening strategy would facilitate development of a rational diagnostic workflow to provide high-quality patient care. [ABSTRACT FROM AUTHOR]

The article explores a specific type of paroxysmal nocturnal haemoglobinuria (PNH) known as ahemolytic PNH or white cell PNH. Unlike typical PNH, this subtype does not exhibit signs of hemolysis but is characterized by bone marrow failure and thrombophilia. The document suggests that this subtype may be caused by a PIGA mutation in a committed progenitor cell rather than a stem cell. The authors recommend considering screening for ahemolytic PNH in cases of thromboembolic events and bone marrow failure without hemolysis. [Extracted from the article]

Objectives: New B-cell markers are needed for monitoring B lymphoblastic leukemia (B-ALL) in the era of immunotherapies directed against CD19 and CD22. The expression of leukocyte immunoglobulin-like receptor subfamily B member 1 (LILRB1) on hematogones in bone marrow (BM) and neoplastic B lymphoblasts has not yet been systematically investigated.Methods: We assessed LILRB1 expression pattern on B cells in 19 control BMs and 22 B-ALL cases by flow cytometry.Results: In all cases, mature B cells and hematogones exhibited a consistent pattern of LILRB1 expression with variable intensity over different stages of maturation, including a characteristic V-shaped pattern on hematogones. While neoplastic B lymphoblasts in all cases expressed LILRB1, the pattern of expression was distinctly abnormal relative to hematogones (loss of the dynamic pattern in all cases and abnormal expression levels in 83% of cases).Conclusions: LILRB1 is a novel diagnostic B-cell marker to aid in distinguishing neoplastic B lymphoblasts from hematogones. [ABSTRACT FROM AUTHOR]

Objectives Our study aimed to develop a machine learning (ML) model to accurately classify acute promyelocytic leukemia (APL) from other types of acute myeloid leukemia (other AML) using multicolor flow cytometry (MFC) data. Multicolor flow cytometry is used to determine immunophenotypes that serve as disease signatures for diagnosis. Methods We used a data set of MFC files from 27 patients with APL and 41 patients with other AML, including those with uncommon immunophenotypes. Our ML pipeline involved training a graph neural network (GNN) to output graph-level labels and identifying the most crucial MFC parameters and cells for predictions using an input perturbation method. Results The top-performing GNN achieved 100% accuracy on the training/validation and test sets on classifying APL from other AML and used MFC parameters similarly to expert pathologists. Pipeline performance is amenable to use in a clinical decision support system, and our deep learning architecture readily enables prediction explanations. Conclusions Our ML pipeline shows robust performance on predicting APL and could be used to screen for APL using MFC data. It also allowed for intuitive interrogation of the model's predictions by clinicians. [ABSTRACT FROM AUTHOR]

Objectives: Bone marrow specimens (aspirate and core biopsy) are invaluable in the diagnosis of hematologic disorders. These can be obtained via the traditional manual needle method (such as the Jamshedi) or the newly developed powered drills, which our teaching institution has recently started using. This study is aimed at comparing the adequacy of bone marrow specimens for pathologic examination obtained from adult patients via the standard manual technique to a powered drill and thereby providing valuable feedback to our clinical colleagues. Methods: A total of 245 serial bone marrow specimens (125 manual and 120 powered) performed by 13 hematology-oncology fellows were included. The specimen quality was obtained by retrospective review of pathology reports that includes information on quality and adequacy of specimens based on presence of particles for aspirate, and presence of at least 10 mm of evaluable marrow in core biopsy. Results: Out of 125 manual marrow aspirate procedures, 77% were adequate for evaluation. Out of 120 powered marrow aspirate procedures, 75% were adequate for evaluation. Of a total of 145 manual core biopsies, 70% were adequate, and of 100 powered core biopsies, 60% were adequate. Conclusion: Our results indicate that both manual and powered bone marrow procedures yield similarly adequate specimens for pathologic evaluation. These results are reassuring and support the continued use of the powered technique in our large teaching institution, as powered techniques have been reported to be more user friendly (less time and more ergonomic) and, more importantly, result in significantly less pain for the patients. [ABSTRACT FROM AUTHOR]

Introduction: Myeloperoxidase (MPO) is considered a specific marker of myeloid/non‐monocytic lineage in the diagnosis of mixed phenotype acute leukemia (MPAL). However, the clinical significance of isolated dim MPO expression in otherwise typical B lymphoblastic leukemia (B‐ALL; referred to as B/myeloid MPALisoMPO) in adult patients is unknown. Methods: We compared flow cytometric immunophenotype and clinicopathological findings among cases of B/myeloid MPALisoMPO (n = 13), other MPAL subtypes (n = 10, B/myeloid and T/myeloid MPAL), B‐ALL (n = 64), and acute myeloid leukemia (AML, n = 58), using the 2016 WHO classification. For MPAL cases, MPO was reported as the percent of MPO positive blasts and its intensity (dim or moderate/strong). The pattern of heterogenous antigen expression (inversely coordinated expression between myeloid and lymphoid markers and cell size) was assessed. Results: Cases of B/myeloid MPALisoMPO showed a fairly homogenous single B‐lineage blast population with dim MPO expression whereas cases of other MPAL subtypes displayed heterogeneous antigen expression and moderate/strong MPO expression. The percent of MPO positive blasts in these two groups was similar. Expressions of CD15, CD117, and monocytic markers were more common in other MPAL than in B/myeloid MPALisoMPO. B/myeloid MPALisoMPO patients had similar overall and leukemia free survivals as B‐ALL patients and better than other MPAL patients. Conclusion: This is the first study to investigate the clinical significance of adult B/myeloid MPALisoMPO using the 2016 WHO classification. Our results suggest that B/myeloid MPALisoMPO clinically behaves more similarly to B‐ALL than to other MPAL subtypes, supporting the 2016 WHO classification to segregate this entity from other MPAL subtypes. [ABSTRACT FROM AUTHOR]

• First case of a cHL with t(11;14) identified by chromosome and FISH analysis with sustained CCND1 expression. • Mantle cell lymphoma and cHL are closely related sharing a common post germinal precursor with t(11;14)+. • Early acquisition of genetic lesions, such as loss of 9q, suggests the potential to develop a cHL phenotype with deregulated cell cycle and signaling pathways. Classic Hodgkin lymphoma (cHL) is characterized by the presence of Hodgkin Reed-Sternberg (HRS) cells. Although HRS cells express PAX5 , cHL frequently lacks other B-cell markers. There is now evidence that HRS cells are monoclonal and are derived from germinal center B-cells. In terms of genetic aberrations, cHL frequently exhibit activated NF-kB signaling pathway. In this study, we present a case of cHL harboring a t(11;14) (q13;q32)/ CCND1 :: IGH , identified by chromosome and fluorescence in situ hybridization analysis and with CCND1 expression in HRS cells. We also analyzed recurrent cytogenetic aberrations in t(11;14) positive mantle cell lymphoma (MCL) and those found in cHL from the literature to assess genetic overlap, clonal evolution, and to identify potential signaling pathways in cHL with CCND1 :: IGH. This analysis suggests the development of t(11;14)+ cHL and MCL from a transformed precursor cell with t(11;14) through genetic evolution and consequent deregulated pathways, including the NF-κB and NOTCH1 signaling. [ABSTRACT FROM AUTHOR]

Objectives: Autologous stem cell transplant with lenalidomide maintenance therapy has greatly improved the relapse-free and overall survival rates of patients with multiple myeloma but also has been associated with an increased risk of secondary B-lymphoblastic leukemia/lymphoma (B-ALL).Methods: We report a comprehensive review of the clinicopathologic features of 2 patients with multiple myeloma who developed secondary B-ALL during lenalidomide maintenance.Results: Our observations showed that the disease may initially present with subtle clinical, morphologic, and flow-cytometric findings. The flow cytometry findings in such cases may initially mimic an expansion of hematogones with minimal immunophenotypic variation. Both patients achieved complete remission of secondary B-ALL after standard chemotherapy; however, one patient continues to have minimal residual disease, and the other experienced relapse. Next-generation sequencing of the relapse specimen showed numerous, complex abnormalities, suggesting clonal evolution.Conclusions: Our findings suggest the need for increased awareness and further study of this unique form of secondary B-ALL. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 36-year-old man who had been diagnosed with hereditary spherocytosis nine years ago and was treated by splenectomy. Results of his bone marrow biopsy and peripheral blood film showed erythrophagocytosis by t-cell lymphoma cells. According to the authors, erythrophagocytosis is a phenomenon that is usually associated with monocytes or macrophages.

Objectives: CD25 expression is associated with t(9;22)(q34;q11)/Philadelphia chromosome translocation (Ph); BCR-ABL1 rearrangement in B lymphoblastic leukemia/lymphoma (B-LL). However, the significance of CD25 expression in Ph negative (Ph-) B-LL regarding residual disease (RD) and genetic abnormalities is largely unknown.Methods: CD25 expression by flow cytometry (FC) was correlated with Ph status in 95 newly diagnosed B-LL patients and with RD status in day 29 marrow measured by FC in the context of cytogenetic risk stratification in Ph- patients.Results: CD25 expression was greater in Ph positive (Ph+) patients (80%) than in Ph- patients (17%), predicting Ph+ with 80% sensitivity and 86% specificity. In Ph- patients, CD25 expression (in 14 patients, 16%) was associated with RD in the cytogenetic intermediate-risk group: detectable RD in 50% of CD25+ patients vs 14% of CD25- patients. Interestingly, one CD25+/Ph- patient had a Ph-like genotype ( ZC3HAV1-ABL2 rearrangement), and another had dual MYC-IGH and BCL2-IGH rearrangements.Conclusions: Our findings not only confirm the predictive power of CD25 expression for Ph+ but also demonstrate that CD25 expression is associated with RD (a biomarker correlated with prognosis) in Ph- patients. The latter finding is likely associated with underlying molecular abnormalities, including Ph-like genotype. [ABSTRACT FROM AUTHOR]

Objectives: CD25 expression is associated with t(9;22)(q34;q11)/Philadelphia chromosome translocation (Ph);BCR-ABL1 rearrangement in B lymphoblastic leukemia/ lymphoma (B-LL). However, the significance of CD25 expression in Ph negative (Ph-) B-LL regarding residual disease (RD) and genetic abnormalities is largely unknown. Methods: CD25 expression by flow cytometry (FC) was correlated with Ph status in 95 newly diagnosed B-LL patients and with RD status in day 29 marrow measured by FC in the context of cytogenetic risk stratification in Ph- patients. Results: CD25 expression was greater in Ph positive (Ph+) patients (80%) than in Ph- patients (17%), predicting Ph+ with 80% sensitivity and 86% specificity. In Ph- patients, CD25 expression (in 14 patients, 16%) was associated with RD in the cytogenetic intermediate-risk group: detectable RD in 50% of CD25+ patients vs 14% of CD25- patients. Interestingly, one CD25+/Ph- patient had a Ph-like genotype (ZC3HAV1-ABL2 rearrangement), and another had dual MYC-IGH and BCL2-IGH rearrangements. Conclusions: Our findings not only confirm the predictive power of CD25 expression for Ph+ but also demonstrate that CD25 expression is associated with RD (a biomarker correlated with prognosis) in Ph- patients. The latter finding is likely associated with underlying molecular abnormalities, including Ph-like genotype. [ABSTRACT FROM AUTHOR]

Chromosome translocations involving an immunoglobulin ( IG ) locus and another gene, either BCL or MYC , are common events in B-cell lymphoma. Occasionally, two IG loci, one with BCL and the other with MYC , are simultaneously involved; such cases are classified as double-hit (DH) lymphomas. These tumors often show intermediate histologic features between those of diffuse large B-cell lymphoma and those of Burkitt lymphoma. Patients with DH lymphoma have a poor prognosis. Rarely, lymphomas in which three IG loci are simultaneously involved with two different BCL genes and MYC have been reported. These cases are classified as triple-hit lymphomas; virtually all these are aggressive tumors with an even worse prognosis. We present here a unique case of follicular lymphoma (FL) with rearranged BCL2 , BCL6 , and BCL1 (also known as CCND1 ) genes. Lymphoma cells at first clinical relapse had a complex karyotype that included a t(3;22)(q27;q11) and t(14;18)(q32;q21). About 15 years after initial diagnosis, the lymphoma cells showed clonal cytogenetic evolution and acquired a t(11;14)(q13;q32). This article is the first case report of a low grade B-cell lymphoma that had three lymphoma-associated reciprocal translocations not involving MYC and that had a long indolent clinical course. [ABSTRACT FROM AUTHOR]

• Dysregulation of MYC is implicated in acute myeloid leukemia (AML). • High MYC protein expression (MYChigh) was detected in AML. • MYChigh did not correlate with MYC abnormalities detected by FISH. • MYChigh predicted an unfavorable prognosis in adult de novo AML. • Routine assessing MYC by immunohistochemistry may improve risk stratification. While dysregulation of MYC has been implicated in acute myeloid leukemia (AML), the impact of MYC protein expression in AML is less well understood. We investigated the correlation of MYC protein expression by immunohistochemistry (MYC-IHC) with MYC abnormalities and prognosis in adult de novo AML. MYC-IHC in bone marrow of patients with untreated AML (n = 58) was assessed and scored as MYClow (0–40 % of blasts) or MYChigh (> 40 % of blasts). This was correlated with MYC abnormalities by fluorescence in situ hybridization (FISH) and prognosis in the context of cytogenetic risk stratification. Residual myeloid disease at the end of induction was assessed by flow cytometry. MYClow and MYChigh were detected in 24 (41 %) and 34 cases (59 %), respectively. Extra copies of MYC were present in 12 % of cases and were not correlated with level of MYC-IHC. No cases had MYC translocation or amplification. Compared to MYClow patients, MYChigh patients had a shorter overall survival in all cytogenetic risk groups (68 vs. 21 months, p = 0.006) and in the intermediate risk group (61 vs. 21 months, p = 0.046). MYChigh patients had a tendency towards detected residual disease at the end of induction in all cytogenetic risk and intermediate risk groups. Regardless of the underlying mechanisms of MYC dysregulation, high level of MYC protein is expressed in the majority of AML and correlated to worse prognosis. Further studies on MYC dysregulation in leukemogenesis and therapy targeting MYC aberration are warranted. [ABSTRACT FROM AUTHOR]

The article describes the case of a 42-year-old white man who developed blastic plasmacytoid dendritic cell neoplasm (BPDCN) two years prior to presentation and presented with pancytopenia and suspected recurrent BPDCN in the bone marrow (BM) without curaneous lesions. Topics discussed include difficulty in BPDCN diagnosis with variable clinical and immunophenotypic overlap with acute myeloid leukaemia (AML) and recurrent KMT2A rearrangement with t(11;19)(q23;p12.3).