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OBJECTIVES: Myeloproliferative neoplasm, unclassifiable (MPN-U, revised to MPN, not otherwise specified in the fifth edition of the World Health Organization classification) is a heterogeneous category of primary marrow disorders with clinical, morphologic, and/or molecular features that preclude classification as a more specific MPN subtype due to stage at diagnosis, overlapping features between MPN subtypes, or the presence of coexisting disorders. Compared with other MPN subtypes, the contribution of the mutational landscape in MPN-U in conjunction with other clinical and morphologic biomarkers to prognosis has been less well investigated. METHODS: We performed a multicenter, retrospective study of MPN-U (94 cases) to better define the clinicopathologic features, genetic landscape, and clinical outcomes, including subgroups of early-stage, advanced-stage, and coexisting disorders. The Dynamic International Prognostic Scoring System (DIPSS) plus scoring system was applied to assess its relevance to MPN-U prognosis. RESULTS: Multivariate analysis demonstrated bone marrow blast count and DIPSS plus score as statistically significant in predicting overall survival. Univariate analysis identified additional potential poor prognostic markers, including abnormal karyotype and absence of JAK2 mutation. Secondary mutations were frequent in the subset analyzed by next-generation sequencing (26/37 cases, 70.3%) with a borderline association between high molecular risk mutations and overall survival. CONCLUSIONS: This study, as one of the largest of MPN-U studies incorporating both clinicopathologic and molecular data, moves toward identification of biomarkers that better predict prognosis in this heterogeneous category.
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Neutrophils are the shortest-lived blood cells, which requires a prodigious degree of proliferation and differentiation to sustain physiologically sufficient numbers and be poised to respond quickly to infectious emergencies. More than 107 neutrophils are produced every minute in an adult bone marrow-a process that is tightly regulated by a small group of cytokines and chemical mediators and dependent on nutrients and energy. Like granulocyte colony-stimulating factor, the primary growth factor for granulopoiesis, they stimulate signalling pathways, some affecting metabolism. Nutrient or energy deficiency stresses the survival, proliferation, and differentiation of neutrophils and their precursors. Thus, it is not surprising that monogenic disorders related to metabolism exist that result in neutropenia. Among these are pathogenic mutations in HAX1, G6PC3, SLC37A4, TAFAZZIN, SBDS, EFL1 and the mitochondrial disorders. These mutations perturb carbohydrate, lipid and/or protein metabolism. We hypothesize that metabolic disturbances may drive the pathogenesis of a subset of inherited neutropenias just as defects in DNA damage response do in Fanconi anaemia, telomere maintenance in dyskeratosis congenita and ribosome formation in Diamond-Blackfan anaemia. Greater understanding of metabolic pathways in granulopoiesis will identify points of vulnerability in production and may point to new strategies for the treatment of neutropenias.
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Enfermedades de la Médula Ósea , Anemia de Fanconi , Neutropenia , Adulto , Humanos , Enfermedades de la Médula Ósea/genética , Anemia de Fanconi/genética , Médula Ósea/patología , Trastornos de Fallo de la Médula Ósea , Neutropenia/patología , Proteínas Adaptadoras Transductoras de Señales , Proteínas de Transporte de Monosacáridos , AntiportadoresRESUMEN
The use of social media in pathology has broadly had a positive impact on pathology education and outreach with the frequent posting of high-quality educational material of potential value to trainees, practicing pathologists, and other clinical and laboratory specialists. These posts are also of potential utility and interest to members of the public, who are now more than ever able to gain a window into the field and the role of pathologists in their medical care. There can be a lighthearted aspect to teaching material with the use of food items/analogies, emojis, or other descriptors, which may cross over into the classroom. However, when pathology discussion is taken to a public forum, such as on Twitter (parent company: X Corp.), there is the potential for posted material to be misunderstood, such as when certain emojis or adjectives may be used to describe a human disease state or patient sample. The authors present examples of potential areas of caution, suggestions of how to create a positive impact, and brief guidelines for social media etiquette on #PathTwitter that may apply to other social media platforms widely used by pathologists (including, but not limited to, Facebook, Instagram, YouTube, and KiKo). While the points discussed here may be common knowledge and well-known to pathologists who use social media for virtual medical education, the concerns mentioned here (such as using language like "beautiful" to describe abnormal mitotic figures and cancer cells) still exist and, henceforth, bear reinforcing.
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Medios de Comunicación Sociales , Estudiantes de Medicina , Humanos , Patólogos , LenguajeRESUMEN
The bone marrow contains peripheral nerves that promote haematopoietic regeneration after irradiation or chemotherapy (myeloablation), but little is known about how this is regulated. Here we found that nerve growth factor (NGF) produced by leptin receptor-expressing (LepR+) stromal cells is required to maintain nerve fibres in adult bone marrow. In nerveless bone marrow, steady-state haematopoiesis was normal but haematopoietic and vascular regeneration were impaired after myeloablation. LepR+ cells, and the adipocytes they gave rise to, increased NGF production after myeloablation, promoting nerve sprouting in the bone marrow and haematopoietic and vascular regeneration. Nerves promoted regeneration by activating ß2 and ß3 adrenergic receptor signalling in LepR+ cells, and potentially in adipocytes, increasing their production of multiple haematopoietic and vascular regeneration growth factors. Peripheral nerves and LepR+ cells thus promote bone marrow regeneration through a reciprocal relationship in which LepR+ cells sustain nerves by synthesizing NGF and nerves increase regeneration by promoting the production of growth factors by LepR+ cells.
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Médula Ósea , Receptores de Leptina , Médula Ósea/metabolismo , Receptores de Leptina/genética , Receptores de Leptina/metabolismo , Células de la Médula Ósea/metabolismo , Factor de Crecimiento Nervioso/metabolismo , Células Madre Hematopoyéticas/metabolismo , Regeneración NerviosaRESUMEN
CONTEXT.: Pathologists play an increasingly critical role in optimizing testing on scant specimens to ensure patients not only receive a correct and timely diagnosis, but also that the appropriate evaluation of biologic markers or "biomarkers" is performed to inform prognosis and best guide therapeutic options. Advances in biomarkers have been particularly impactful in the field of hematopathology, where the identification of cytogenetic abnormalities, specific mutations, morphologic features, and/or protein expression may help guide clinical decision-making, including type and intensity of therapy and eligibility for clinical trials. OBJECTIVE.: To stay up to date with advances in relevant biomarkers for diagnosis, prognosis, and therapy. The Cancer Biomarkers Conference (CBC) has been developed as a highly focused meeting to provide key biomarker updates across medical fields with the inclusion of industry partners, reach a broader audience, and cross-pollinate emerging areas for biomarker application and future discovery. The objective of this article is to raise awareness of the potential utility of such meetings for improving patient care and facilitating collaboration. DATA SOURCES.: Recently released guidelines related to B-cell lymphoma diagnosis from the World Health Organization and International Consensus Classification and associated manuscripts are reviewed. Material presented at the CBC conference is summarized. CONCLUSIONS.: This article covers highlights of the updates presented on B-cell lymphoma biomarkers at the most recent Cancer Biomarkers Conference in Flowood, Mississippi, in September 2022.
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ABSTRACT: The spatial anatomy of hematopoiesis in the bone marrow (BM) has been extensively studied in mice and other preclinical models, but technical challenges have precluded a commensurate exploration in humans. Institutional pathology archives contain thousands of paraffinized BM core biopsy tissue specimens, providing a rich resource for studying the intact human BM topography in a variety of physiologic states. Thus, we developed an end-to-end pipeline involving multiparameter whole tissue staining, in situ imaging at single-cell resolution, and artificial intelligence-based digital whole slide image analysis and then applied it to a cohort of disease-free samples to survey alterations in the hematopoietic topography associated with aging. Our data indicate heterogeneity in marrow adipose tissue (MAT) content within each age group and an inverse correlation between MAT content and proportions of early myeloid and erythroid precursors, irrespective of age. We identify consistent endosteal and perivascular positioning of hematopoietic stem and progenitor cells (HSPCs) with medullary localization of more differentiated elements and, importantly, uncover new evidence of aging-associated changes in cellular and vascular morphologies, microarchitectural alterations suggestive of foci with increased lymphocytes, and diminution of a potentially active megakaryocytic niche. Overall, our findings suggest that there is topographic remodeling of human hematopoiesis associated with aging. More generally, we demonstrate the potential to deeply unravel the spatial biology of normal and pathologic human BM states using intact archival tissue specimens.
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Inteligencia Artificial , Células Madre Hematopoyéticas , Humanos , Ratones , Animales , Células Madre Hematopoyéticas/patología , Médula Ósea/patología , Hematopoyesis/fisiología , EnvejecimientoRESUMEN
NPM1 mutated non-AML myeloid neoplasms (MN; <20% blasts) are characterized by an aggressive clinical course in a few studies. In this retrospective study, we evaluate the clinicopathologic and immunohistochemical features of non-AML MN patients with NPM1 mutations. We assessed NPM1 mutation by targeted next generation sequencing (NGS). Cytoplasmic NPM1 expression was assessed by immunohistochemistry (IHC) on formalin-fixed, formic acid-decalcified bone marrow biopsy specimens. We evaluated 34 non-AML MN patients with NPM1 mutations comprising MDS (22), MPN (3) and MDS/MPN (9). They commonly presented with anemia (88%), thrombocytopenia (58%) and leukopenia (50%). Bone marrow dysplasia was common (79%). The karyotype was often normal (64%). NGS for MN-associated mutations performed in a subset of the patients showed a median of 3 mutations. NPM1 mutations were more often missense (c.859C > T p. L287F; 65%) than frameshift insertion/duplication (35%) with median variant allele frequency (VAF; 9.7%, range 5.1%-49.8%). Mutated NPM1 by IHC showed cytoplasmic positivity in 48% and positivity was associated with higher VAF. The median overall survival (OS) in this cohort was 70 months. Nine patients (26%) progressed to AML. OS in patients who progressed to AML was significantly shorter than the one of patients without progression to AML (OS 20 vs. 128 months, respectively, log rank p = 0.05). NPM1 mutated non-AML MN patients commonly had cytopenias, dysplasia, normal karyotype, mutations in multiple genes, and an unfavorable clinical outcome, including progression to AML. Our data demonstrated that IHC for NPM1 can be a useful supplementary tool to predict NPM1 mutation in some non-AML MN; however, genetic testing cannot be replaced by IHC assessment.
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Leucemia Mieloide Aguda , Trastornos Mieloproliferativos , Humanos , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Nucleofosmina , Leucemia Mieloide Aguda/patología , Inmunohistoquímica , Estudios Retrospectivos , MutaciónRESUMEN
Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is recurrently mutated in epigenetic pathway genes. We studied the myeloid-related genetic mutations in a cohort of five patients with BPDCN and one paired relapse case at our institution and identified a high frequency of biallelic TET2 and canonical ASXL1 (c.1934dupG) mutations. The number of cases is small, but the variant allele fraction (VAF) sums of the TET2 mutations, as well as the persistence of TET2 mutations in a case of relapsed BPDCN, suggest an ancestral/founder nature of TET2 clones in the cases. Further literature review shows a high frequency of biallelic TET2 mutations in reported cases of BPDCN.
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How are haematopoietic stem cells (HSCs) protected from inflammation, which increases with age and can deplete HSCs? Adiponectin, an anti-inflammatory factor that is not required for HSC function or haematopoiesis, promotes stem/progenitor cell proliferation after bacterial infection and myeloablation. Adiponectin binds two receptors, AdipoR1 and AdipoR2, which have ceramidase activity that increases upon adiponectin binding. Here we found that adiponectin receptors are non-cell-autonomously required in haematopoietic cells to promote HSC quiescence and self-renewal. Adiponectin receptor signalling suppresses inflammatory cytokine expression by myeloid cells and T cells, including interferon-γ and tumour necrosis factor. Without adiponectin receptors, the levels of these factors increase, chronically activating HSCs, reducing their self-renewal potential and depleting them during ageing. Pathogen infection accelerates this loss of HSC self-renewal potential. Blocking interferon-γ or tumour necrosis factor signalling partially rescues these effects. Adiponectin receptors are thus required in immune cells to sustain HSC quiescence and to prevent premature HSC depletion by reducing inflammation.
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Adiponectina , Receptores de Adiponectina , Adiponectina/genética , Adiponectina/metabolismo , Adulto , Células Madre Hematopoyéticas/metabolismo , Humanos , Inflamación/metabolismo , Interferón gamma/genética , Interferón gamma/metabolismo , Receptores de Adiponectina/genética , Receptores de Adiponectina/metabolismo , Factores de Necrosis Tumoral/metabolismoRESUMEN
Merkel cell carcinoma (MCC) is a rare but aggressive neuroendocrine carcinoma of the skin, often associated with polyomavirus and ultra-violet light exposure. Immunosuppression is associated with increased risk of development of MCC, including that associated with hematolymphoid disorders such as chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). We sought to determine whether MCC arising in patients with hematologic disorders showed unique features. Searching archived material at three institutions, we identified 13 patients with MCC and at least one hematologic malignancy and 41 patients with MCC with no reported hematologic malignancy. CLL/SLL was the most common hematologic disorder in this setting (9/13 cases). Clinical history, variation in morphologic appearance, unusual site distribution and concern for progression of underlying hematologic disease all contributed to potential diagnostic challenges. Overlapping marker expression between MCC and hematologic neoplasms created potential diagnostic pitfalls (e.g. CD138, Pax5, TdT, Bcl2, CD56, and CD117). In addition, we newly identify expression of CD5 and LEF-1 in a subset of MCC, including in patients with CLL/SLL. MCC in patients with hematologic malignancy were more common in men (92% versus 59%, p < 0.05) and showed an unusual site predilection to non-sun exposed sites (3/13 on the buttocks) with none presenting on the face or scalp. By contrast, face or scalp lesions were common in MCC without an associated hematologic malignancy (17/41, p < 0.05). Our findings reaffirm the need for skin surveillance in the setting of immune deficiency and for vigilance to identify unusual presentations of MCC in patients with or without hematologic disorders.
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Carcinoma de Células de Merkel/patología , Enfermedades Hematológicas/patología , Neoplasias Cutáneas/patología , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células de Merkel/complicaciones , Femenino , Enfermedades Hematológicas/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Cutáneas/complicacionesRESUMEN
Posttransplant lymphoproliferative disorder (PTLD) includes a range of abnormal lymphoid proliferation following solid organ or allogeneic hematopoietic stem cell transplantation (HSCT), often associated with Epstein-Barr virus (EBV) infection. Treatment generally incudes rituximab, a chimeric monoclonal antibody directed against CD20. Here we present a 56-year-old woman with EBV-associated PTLD following allogeneic HSCT who was intolerant of rituximab. The patient was instead treated with ofatumumab, a fully human monoclonal antibody directed against CD20, with significant response in EBV viral load and lymphadenopathy. Ofatumumab could represent an important treatment option for patients unable to tolerate rituximab.
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Infecciones por Virus de Epstein-Barr , Trasplante de Células Madre Hematopoyéticas , Trastornos Linfoproliferativos , Femenino , Humanos , Persona de Mediana Edad , Infecciones por Virus de Epstein-Barr/complicaciones , Infecciones por Virus de Epstein-Barr/tratamiento farmacológico , Rituximab/uso terapéutico , Herpesvirus Humano 4/fisiología , Trastornos Linfoproliferativos/tratamiento farmacológico , Trastornos Linfoproliferativos/etiología , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Anticuerpos Monoclonales/uso terapéuticoAsunto(s)
Linfoma de Burkitt , Neoplasias del Sistema Nervioso Central , Protocolos de Quimioterapia Combinada Antineoplásica , Linfoma de Burkitt/diagnóstico , Linfoma de Burkitt/tratamiento farmacológico , Linfoma de Burkitt/patología , Neoplasias del Sistema Nervioso Central/diagnóstico , Humanos , PronósticoRESUMEN
Epstein-Barr virus (EBV) is a ubiquitous gammaherpesvirus with >90% of the adult population worldwide harbouring latent infection. A small subset of those infected develop EBV-associated neoplasms, including a range of lymphoproliferative disorders (LPD). The diagnostic distinction of these entities appears increasingly relevant as our understanding of EBV-host interactions and mechanisms of EBV-driven lymphomagenesis improves. EBV may lower the mutational threshold for malignant transformation, create potential vulnerabilities related to viral alteration of cell metabolism and allow for improved immune targeting. However, these tumours may escape immune surveillance by affecting their immune microenvironment, limiting viral gene expression or potential loss of the viral episome. Methods to manipulate the latency state of the virus to enhance immunogenicity are emerging as well as the potential to detect so-called 'hit and run' cases where EBV has been lost. Finally, measurement of EBV DNA remains an important biomarker for screening and monitoring of LPD. Methods to distinguish EBV DNA derived from virions during lytic activation from latent, methylated EBV DNA present in EBV-associated neoplasms may broaden the utility of this testing, particularly in patients with compromised immune function. We highlight some of these emerging areas relevant to the diagnosis and treatment of EBV-associated LPD with potential applicability to other EBV-associated neoplasms.
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Infecciones por Virus de Epstein-Barr/complicaciones , Trastornos Linfoproliferativos/virología , Humanos , Trastornos Linfoproliferativos/diagnóstico , Trastornos Linfoproliferativos/terapiaRESUMEN
The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.1.
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This review describes how Twitter is currently used by laboratory professionals for education, research, and networking. This platform has a global audience. It enables users to post information publicly, easily, rapidly, and free of charge. The absence of hierarchies enables interactions that may not be feasible offline. Laboratory professionals teach thousands of people using text, images, polls, and videos. Academic discussion flourishes without paywalls. Published research is shared faster than ever before, articles are discussed in online journal clubs, and research collaborations are facilitated. Pathologists network globally and make new friends within and beyond their specialty. Pathology departments and residency programs showcase trainees and faculty and celebrate graduations. As users in one time zone go to bed, others who are just waking up begin to read and tweet, creating a 24/7/365 live global online conference. We encourage others to plug into the power of Twitter, the network that never sleeps.
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Internado y Residencia , Medios de Comunicación Sociales , Docentes , HumanosRESUMEN
Stromal cells in adult bone marrow that express leptin receptor (LEPR) are a critical source of growth factors, including stem cell factor (SCF), for the maintenance of haematopoietic stem cells and early restricted progenitors1-6. LEPR+ cells are heterogeneous, including skeletal stem cells and osteogenic and adipogenic progenitors7-12, although few markers have been available to distinguish these subsets or to compare their functions. Here we show that expression of an osteogenic growth factor, osteolectin13,14, distinguishes peri-arteriolar LEPR+ cells poised to undergo osteogenesis from peri-sinusoidal LEPR+ cells poised to undergo adipogenesis (but retaining osteogenic potential). Peri-arteriolar LEPR+osteolectin+ cells are rapidly dividing, short-lived osteogenic progenitors that increase in number after fracture and are depleted during ageing. Deletion of Scf from adult osteolectin+ cells did not affect the maintenance of haematopoietic stem cells or most restricted progenitors but depleted common lymphoid progenitors, impairing lymphopoiesis, bacterial clearance, and survival after acute bacterial infection. Peri-arteriolar osteolectin+ cell maintenance required mechanical stimulation. Voluntary running increased, whereas hindlimb unloading decreased, the frequencies of peri-arteriolar osteolectin+ cells and common lymphoid progenitors. Deletion of the mechanosensitive ion channel PIEZO1 from osteolectin+ cells depleted osteolectin+ cells and common lymphoid progenitors. These results show that a peri-arteriolar niche for osteogenesis and lymphopoiesis in bone marrow is maintained by mechanical stimulation and depleted during ageing.
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Arteriolas , Linfopoyesis , Osteogénesis , Nicho de Células Madre , Tejido Adiposo/citología , Envejecimiento , Animales , Células de la Médula Ósea/citología , Huesos/citología , Femenino , Factores de Crecimiento de Célula Hematopoyética/metabolismo , Lectinas Tipo C/metabolismo , Linfocitos/citología , Masculino , Ratones , Receptores de Leptina/metabolismo , Factor de Células Madre , Células del Estroma/citologíaRESUMEN
The unique architecture of the spleen enables it to play a key role in the interactions between the circulatory, reticuloendothelial and immune systems. Response to circulating antigens in the setting of infection, autoimmune disease or other conditions may result in a range of benign lymphoid proliferations. Moreover, patients with underlying immune deficiency may also show abnormal lymphoid proliferations within the spleen. This review will highlight the histologic, immunophenotypic and clinical features of reactive lymphoid proliferations to aid in their recognition and provide a context for understanding their development in relation to normal splenic structure and function.
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Síndromes de Inmunodeficiencia , Bazo , Humanos , Bazo/crecimiento & desarrollo , Bazo/inmunologíaRESUMEN
Hematopathologists are witnessing very exciting times, as a new era of unsurpassed technological advances is unfolding exponentially, enhancing our understanding of diseases at the genomic and molecular levels. In the evolving field of precision medicine, our contributions as hematopathologists to medical practice are of paramount importance. Social media platforms such as Twitter have helped facilitate and enrich our professional interactions and collaborations with others in our field and in other medical disciplines leading to a more holistic approach to patient care. These platforms also have created a novel means for instantaneous dissemination of new findings and recent publications, and are proving to be increasingly useful tools that can be harnessed to expand our knowledge and amplify our presence in the medical community. In this Editorial, we share our experience as hematopathologists with Twitter, and how we leveraged this platform to boost scholarly activities within and beyond our subspecialty, and as a powerful medium for worldwide dissemination of educational material and to promote our remote teaching activities during the COVID-19 pandemic.
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COVID-19 , Educación Médica Continua , Hematología/educación , Patólogos/educación , Patología/educación , Comunicación Académica , Medios de Comunicación Sociales , Congresos como Asunto , Humanos , Difusión de la Información , Especialización , Texas , Comunicación por VideoconferenciaRESUMEN
PURPOSE OF REVIEW: Social media engagement by medical professionals with varied background subspecialties has steadily gained popularity in recent years. As a heavily visual discipline, pathology has been able to leverage social media platforms for trainee education, curbside and official consultations, interdisciplinary communication, and interactions among medical professionals and patient education. The pathology community has been at the forefront of using social media as an educational forum, and the hematopathology community has emerged as one of the strongest and most influential presences on these online platforms. In this review, we perform an in-depth analysis of various Twitter metrics to demonstrate key trends in the usage of social media as it pertains to hematopathology using the hashtag #Hemepath and we describe specific details on how hematopathologists have managed to take advantage of Twitter in furthering our mission of advancing medical education and disseminating knowledge using these innovative virtual educational experiences. RECENT FINDINGS: The hematopathology community has a great degree of enthusiasm among residents, fellows, and faculty in sharing educational material using case-based examples, participating in group-based online activities, introducing new publications by article authors or readership, and disseminating educational "pearls" from medical conferences, using hashtags and digital images that otherwise would not be readily available to many around the globe. This practice is helping reshape the structure of our field and is providing opportunities to optimize the educational experience by enhancing the instant exposure to cutting-edge information and expert opinions, among other valuable features. The hematopathology community has leveraged social media platforms for disseminating educational material and strengthening interdisciplinary interactions and is a "poster child" for a medical subspecialty that has thrived and flourished by more broadly adopting virtual educational platforms. We hope that this review will provide details on how social media platforms can be used by others in the medical field to achieve similar goals.