Progression in Myeloid Neoplasms: Beyond the Myeloblast.

Disease progression in myelodysplastic syndromes (MDS), myelodysplastic-myeloproliferative neoplasms (MDS/MPN), and myeloproliferative neoplasms (MPN), altogether referred to as myeloid neoplasms (MN), is a major source of mortality. Apart from transformation to acute myeloid leukemia, the clinical progression of MN is mostly due to the overgrowth of pre-existing hematopoiesis by the MN without an additional transforming event. Still, MN may evolve along other recurrent yet less well-known scenarios: (1) acquisition of MPN features in MDS or (2) MDS features in MPN, (3) progressive myelofibrosis (MF), (4) acquisition of chronic myelomonocytic leukemia (CMML)-like characteristics in MPN or MDS, (5) development of myeloid sarcoma (MS), (6) lymphoblastic (LB) transformation, (7) histiocytic/dendritic outgrowths. These MN-transformation types exhibit a propensity for extramedullary sites (e.g., skin, lymph nodes, liver), highlighting the importance of lesional biopsies in diagnosis. Gain of distinct mutations/mutational patterns seems to be causative or at least accompanying several of the above-mentioned scenarios. MDS developing MPN features often acquire MPN driver mutations (usually JAK2), and MF. Conversely, MPN gaining MDS features develop, e.g., ASXL1, IDH1/2, SF3B1, and/or SRSF2 mutations. Mutations of RAS-genes are often detected in CMML-like MPN progression. MS ex MN is characterized by complex karyotypes, FLT3 and/or NPM1 mutations, and often monoblastic phenotype. MN with LB transformation is associated with secondary genetic events linked to lineage reprogramming leading to the deregulation of ETV6, IKZF1, PAX5, PU.1, and RUNX1. Finally, the acquisition of MAPK-pathway gene mutations may shape MN toward histiocytic differentiation. Awareness of all these less well-known MN-progression types is important to guide optimal individual patient management.

Co-occurring mutations in ASXL1, SRSF2, and SETBP1 define a subset of myelodysplastic/ myeloproliferative neoplasm with neutrophilia.

Identification of genomic signatures with consistent clinicopathological features in myelodysplastic/myeloproliferative neoplasm (MDS/MPN) is critical for improved diagnosis, elucidation of biology, inclusion in clinical trials, and development of therapies. We describe clinical and pathological features with co-existence of mutations in ASXL1 (missense or nonsense), SRSF2, and SKI homologous region of SETBP1, in 18 patients. Median age was 68 years with a male predominance (83%). Leukocytosis and neutrophilia were common at presentation. Marrow features included hypercellularity, granulocytic hyperplasia with megakaryocytic atypia, while the majority had myeloid hyperplasia and/or erythroid hypoplasia, myeloid dysplasia, and aberrant CD7 expression on blasts. Mutations in growth signaling pathways (RAS or JAK2) were noted at diagnosis or acquired during the disease course in 83% of patients. Two patients progressed upon acquisition of FLT3-TKD (acute myeloid leukemia) or KIT (aggressive systemic mastocytosis) mutations. The prognosis is poor with only two long-term survivors, thus far, who underwent blood or marrow transplantation. We propose that the presence of co-occurring ASXL1, SRSF2, and SETBP1 mutations can be diagnostic of a subtype of MDS/MPN with neutrophilia if clinical and morphological findings align. Our report underscores the association between genotype and phenotype within MDS/MPN and that genomic signatures should guide categorization of these entities.

Genomics of myelodysplastic/myeloproliferative neoplasm.

Myelodysplastic/ Myeloproliferative neoplasms (MDS/MPN) demonstrate overlapping pathologic and molecular features of myelodysplastic (MDS) and myeloproliferative (MPN) neoplasms. Diagnosis is difficult based on morphology alone, requiring exclusion of various non-neoplastic causes for CBC abnormalities and morphologic findings and other myeloid neoplasms. Identifying a clonal abnormality by cytogenetics or molecular studies has vastly improved our ability to diagnose MDS/MPN and has been incorporated in the different classification schemas. Currently two separate classification systems are in use- The 5th edition WHO and international consensus classification. The two competing classifications emphasize genetic work-up and are similar on many levels; however, they do introduce diagnostic dilemma when diagnosing certain entities such as chronic myelomonocytic leukemia in the presence of NPM1 mutations. The genetic profile overlaps among different subentities; however, the combination and the incidence of mutations; together with the clinical features and morphology helps in further subclassification. In this review, we discuss the advances in molecular characterization of MDS/MPN. We attempt to summarize the differences between the various classification schemes, and highlight the changes made in the diagnostic criteria.

Pathogenic Mutations and Atypical Flow Cytometric Findings Characterize the Majority of Unclassifiable Myelodysplastic/Myeloproliferative Neoplasms.

OBJECTIVES: Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are a group of rare and heterogeneous hematopoietic disorders that frequently present a diagnostic challenge. Here we present our institutional experience with next-generation sequencing (NGS), together with morphologic, flow cytometric, and cytogenetic evaluation, in the diagnosis of MDS/MPN, with particular emphasis on MDS/MPN unclassifiable (MPN-U). METHODS: We evaluated the morphologic, flow cytometric, cytogenetic, and molecular characteristics of all MDS/MPN cases that underwent NGS at our institution between April 2016 and February 2019. RESULTS: Thirty-seven cases of MDS/MPN were identified, including 14 cases of MDS/MPN-U. Ninety-seven percent harbored mutations and immunophenotypic aberrancies (36/37), while only 38% had cytogenetic abnormalities (12/32). The MDS/MPN-U group had the highest rate of myeloblast phenotypic abnormalities and had a high mutation rate of approximately 2.7 mutated genes per case, most commonly in JAK2, SRSF2, and ASXL1. CONCLUSIONS: No single ancillary study was abnormal in every case, but all cases had at least one abnormal finding, demonstrating the usefulness of a multiparameter approach to the diagnosis of MDS/MPN. Although a few specific mutations were found exclusively in MDS/MPN-U and JAK2 mutations were most prevalent, larger studies are needed to determine whether MDS/MPN-U has a mutational "fingerprint," which may aid in diagnosis and targeted therapy.

Co-mutation pattern, clonal hierarchy, and clone size concur to determine disease phenotype of SRSF2P95-mutated neoplasms.

Somatic mutations in splicing factor genes frequently occur in myeloid neoplasms. While SF3B1 mutations are associated with myelodysplastic syndromes (MDS) with ring sideroblasts, SRSF2P95 mutations are found in different disease categories, including MDS, myeloproliferative neoplasms (MPN), myelodysplastic/myeloproliferative neoplasms (MDS/MPN), and acute myeloid leukemia (AML). To identify molecular determinants of this phenotypic heterogeneity, we explored molecular and clinical features of a prospective cohort of 279 SRSF2P95-mutated cases selected from a population of 2663 patients with myeloid neoplasms. Median number of somatic mutations per subject was 3. Multivariate regression analysis showed associations between co-mutated genes and clinical phenotype, including JAK2 or MPL with myelofibrosis (OR = 26.9); TET2 with monocytosis (OR = 5.2); RAS-pathway genes with leukocytosis (OR = 5.1); and STAG2, RUNX1, or IDH1/2 with blast phenotype (MDS or AML) (OR = 3.4, 1.9, and 2.1, respectively). Within patients with SRSF2-JAK2 co-mutation, JAK2 dominance was invariably associated with clinical feature of MPN, whereas SRSF2 mutation was dominant in MDS/MPN. Within patients with SRSF2-TET2 co-mutation, clinical expressivity of monocytosis was positively associated with co-mutated clone size. This study provides evidence that co-mutation pattern, clone size, and hierarchy concur to determine clinical phenotype, tracing relevant genotype-phenotype associations across disease entities and giving insight on unaccountable clinical heterogeneity within current WHO classification categories.

Proliferative activity is disturbed in myeloproliferative neoplasms (MPN), myelodysplastic syndrome (MDS), and MDS/MPN diseases. Differences between MDS and MDS/MPN.

The proliferation marker Ki-67 is widely used within the field of diagnostic histopathology as a prognostic marker for solid cancers. However, Ki-67 is hardly used for prognostic and diagnostic purposes in flow cytometric analyses of hematologic neoplasms. In the present study, we investigated to what extent the proliferative activity, as determined by Ki-67 expression, is disturbed in myeloproliferative neoplasms (MPN), myelodysplastic syndrome (MDS), and MDS/MPN diseases. Bone marrow aspirates from 74 patients suffering from MPN, MDS, or MDS/MPN, and aspirates from 50 non-malignant cases were analyzed by flow cytometry for Ki-67 expression in the erythro-, myelo-, and monopoiesis. Ki-67 expression was used to investigate the proliferative activity during the various maturation steps within these hematopoietic cell lineages. In the MPN patient cohort, the proliferative activity of all cell lineages is significantly higher during almost all maturation stages compared to those of the benign control cohort. In the MDS and MDS/MPN cohort, a significantly lower proliferative activity is observed in the early maturation stages. In the MDS/MPN patient cohort, increased proliferative activity is seen in the later stages of the maturation. MDS and MDS/MPN display a distinct pattern in the proliferating fraction of maturing hematopoietic cells. This could become of added value in order to classify these malignancies based on their biological background and behavior, as well as in gaining a better understanding into the pathobiology of these malignancies.

Progression, transformation, and unusual manifestations of myelodysplastic syndromes and myelodysplastic-myeloproliferative neoplasms: lessons learned from the XIV European Bone Marrow Working Group Course 2019.

Disease progression in myelodysplastic syndromes (MDS) and myelodysplastic-myeloproliferative neoplasms (MDS/MPN) is a major source of mortality. The European Bone Marrow Working Group organized a dedicated workshop to address MDS and MDS/MPN progression, and myeloid neoplasms with histiocytic and lymphoblastic outgrowths in 2019 in Frankfurt, Germany. In this report, we summarize clinical, histopathological, and molecular features of 28 cases. Most cases illustrate that prognostic mutational profiles change during follow-up due to accumulation of high-risk mutations in the trunk clone, and that results from repeated molecular testing can often explain the clinical progression, suggesting that regular genetic testing may predict transformation by early detection of aggressive clones. Importantly, identical mutations can be linked to different clinical behaviors or risks of fibrotic progression and/or transformation in a context-dependent manner, i.e., MDS or MDS/MPN. Moreover, the order of mutational acquisition and the involved cell lineages matter. Several cases exemplify that histiocytic outgrowths in myeloid neoplasms are usually accompanied by a more aggressive clinical course and may be considered harbinger of disease progression. Exceptionally, lymphoblastic transformations can be seen. As best estimable, the histiocytic and lymphoblastic compounds in all occasions were clonally related to the myeloid compound and-where studied-displayed genomic alterations of, e.g., transcription factor genes or genes involved in MAPK signaling that might be mechanistically linked to the respective type of non-myeloid outgrowth.

Clinical analysis and literature review of a case with the myelodysplastic syndrome/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis.

Objective: Myelodysplastic syndrome/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T) is a new disease entity in the 2016 WHO classification, characterized by anemia, thrombocytosis and bone marrow ring sideroblasts. We herein reported a case of MDS/MPN-RS-T and discuss its clinical characteristics. Methods: A 69-year-old woman presented to our hospital with recurrent dizziness and fatigue. Hematologic investigations, bone marrow analysis and genomic DNA sequencing studies were performed. Results: Peripheral blood testing showed normocytes anemia and thrombocytosis, and bone marrow analysis revealed hypercellular with clusters of megakaryocytes and 95% ring sideroblasts (RS). She had a normal karyotype and was found to have SF3B1 mutations. Decitabine therapy produced a clinical response and disease remission in this patient. Conclusions: Our report provides a definite conceptual framework for a better understanding of the characteristics of MDS/MPN-RS-T.

Giant-cell arteritis associated with myelodysplastic syndrome: French multicenter case control study and literature review.

INTRODUCTION: Myelodysplastic syndromes (MDS) and MDS/myeloproliferative neoplasms (MDS/MPN) can be associated with giant cell arteritis (GCA). In this nationwide study by the "French Network of dysimmune disorders associated with hemopathies" (MINHEMON) the objective was to evaluate characteristics, treatment and outcome of GCA MDS-MDS/MPN. PATIENTS AND METHODS: Retrospective analysis of patients that presented a MDS or MDS/MPN associated with GCA. Treatment efficiency, relapse-free and overall survival of GCA MDS-MDS/MPN were compared to GCA alone. RESULTS: Twenty-one patients with GCA MDS-MDS/MPN were included with median age 76 [42-92], M/F ratio 2.5, 8 MDS with multilineage dysplasia (38%), 4 chronic myelomonocytic leukemia (19%), at low or intermediate risk according to IPPS and IPSS-R. The prevalence of headaches, jaw claudication and anterior ischemic optic neuropathy was significantly lower in patients with GCA MDS-MDS/MPN compared to idiopathic GCA (14.3%, 0% and 0% versus 30%, 25%, and 25%, respectively; p < .05). Other clinical and histology findings were similar. All GCA patients received steroid therapy as first-line treatment. Complete or partial response was observed in 14 GCA MDS-MDS/MPN patients (66.7%), of whom 6 (28.6%) received combined immunosuppressive therapies (versus 10% of idiopathic GCA; p = .07). Relapse incidence was similar in the two groups. Steroid dependence was more frequent among GCA MDS-MDS/MPN patients (12 (57%) versus 18 (22.5%); p < .05). Relapse-free and steroid-free survivals were significantly decreased in GCA MDS-MDS/MPN patients (log rank 0.002 and 0.049 respectively), but not overall survival. CONCLUSION: Characteristics of GCA MDS-MDS/MPN seem different than idiopathic GCA, with a distinct clinical phenotype and poorer outcome with a higher risk of steroid dependence and relapse.

Análisis integrado clínico, molecular e histopatológico de la médula ósea en las neoplasias mieloproliferativas crónicas / Comprehensive clinical, molecular and histopathological analysis of bone marrow in chronic myeloproliferative neoplasia

OBJETIVOS: Análisis de las posibles correlaciones entre las alteraciones moleculares en los genes JAK2, MPL y CALR, el patrón morfológico de la médula ósea y el perfil clínico-hematológico de los pacientes. PACIENTES Y MÉTODOS: Se trata de un estudio retrospectivo que incluye 140 pacientes con diagnóstico de neoplasias mieloproliferativas Filadelfia negativas (NMP Fi−) de un único centro. RESULTADOS: En la TE, los pacientes con la mutación el JAK2 V617F, presentaron un mayor número de leucocitos y neutrófilos que aquellos que presentaron la mutación en CALR. Los CALR mutados obtuvieron un mayor número de plaquetas y mayor necesidad de tratamiento citorreductor. Estos hallazgos apoyan el hecho de que el estado mutacional en la TE parece definir subtipos de pacientes con un curso clínico y pronóstico substancialmente diferentes. En la MF el estado mutacional parece influir en los cambios histopatológicos encontrados en la BMO, lo que no ocurrió en PV y TE

OBJECTIVES: To analyse the possible correlation between molecular changes in the JAK2, MPL and CALR genes, the morphological pattern of bone marrow and the clinical-haematologic profile of patients. PATIENTS AND METHODS: We conducted a retrospective study that included 140 patients diagnosed with Philadelphia-negative myeloproliferative neoplasia (Ph-MPN) in a single centre. RESULTS: In essential thrombocythaemia (ET), the patients with the JAK2 V617F mutation presented more leucocytes and neutrophils than patients who presented the CALR mutation, who had more platelets and a greater need for cytoreductive therapy. These findings support the fact that the mutational state in ET appears to define subtypes of patients with substantially different clinical courses and prognoses. In myelofibrosis, the mutational state appears to influence the histopathological changes found in the bone marrow biopsy, which did not occur in polycythaemia vera or ET