MLL-MLLT10 fusion in acute monoblastic leukemia: variant complex rearrangements and 11q proximal breakpoint heterogeneity

Cytogenetic studies of acute monoblastic leukemia cases presenting MLL-MLLT10 (alias MLL-AF10) fusion show a broad heterogeneity of chromosomal breakpoints. We present two new pediatric cases (French-American-British type M5) with MLL-MLLT10 fusion, which we studied with fluorescence in situ hybridization. In both we detected a paracentric inversion of the 11q region that translocated onto chromosome 10p12; one case displayed a variant complex pattern. We review the cytogenetic molecular data concerning the proximal inversion breakpoint of 11q and confirm its heterogeneit

Indigenous case of mycetoma by Actinomadura madurae in Paraná (Entre Ríos, Argentina): case report and literature review of the argentinian casuistry

El micetoma es una infección granulomatosa crónica que involucra tejidos cutáneos, subcutáneos y eventualmente músculo y hueso. Puede ser causada por bacterias Gram positivas filamentosas (actinomicetomas) o por hongos (eumicetomas). Es una infección endémica de zonas subtropicales con baja humedad relativa. El objetivo de este trabajo es el de presentar un caso de actinomicetoma causado por Actinomadura madurae autóctono de la ciudad de Paraná (Entre Ríos) con el fin de demostrar que pueden darse casos esporádicos por fuera de las zonas endémicas descritas. Además, se realizó una revisión bibliográfica de los casos de micetoma descritos en Argentina y se los comparó con el caso reportado.Mycetoma is a chronic granulomatous infection involving skin, subcutaneous tissue and eventualy muscle and bone. It can be caused by Gram positive filamentous bacteria (actinomycetomas) or fungi (eumicetomas). It is an endemic infection in subtropical areas with low relative humidity. The aim of this work is to present a case of actinomycetoma caused by Actinomadura madurae in a patient from Paraná city (Entre Rios) to demonstrate that sporadic mycetoma cases may occur outside the described endemic areas. In addition, a literature review of Argentinian mycetoma cases was performed.Fil: Dudiuk, Catiana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; ArgentinaFil: Theill, L.. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; ArgentinaFil: Moyano, Susana. Laboratorio Privado Avenida. Paraná, Entre Ríos; ArgentinaFil: Barbagelata, María Sol. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; ArgentinaFil: Leonardelli, Florencia. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Unidad de Administración Territorial; ArgentinaFil: Macedo, Daiana. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; ArgentinaFil: Latorre Rapella, María Gabriela. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; ArgentinaFil: Acosta, A.. Laboratorio Privado Avenida. Paraná, Entre Ríos; ArgentinaFil: Gamarra, S.. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; ArgentinaFil: Garcia, Guillermo Manuel. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin

P185 | VENOUS THROMBOEMBOLISM IN MULTIPLE MYELOMA: ASSESSMENT OF THE CURRENT RISK MODELS AND THE ROLE OF HYPERCALCEMIA AS A POTENTIAL CONTRIBUTING FACTOR.

Background Patients (pts) with Multiple Myeloma (MM) have a 9-fold increased risk of venous thromboembolic events (VTE). Prophylaxis effectively reduces VTE risk and is initiated after applying two different scores: SAVED, which is validated for pts receiving immunomodulatory drugs (IMiDs), and IMPEDE-VTE, which has a dynamic use and doesn’t consider disease activity markers. Aims To estimate the incidence of VTE in a cohort of MM pts from our Center, evaluate the performance of SAVED and IMPEDE-VTE in this cohort and identify additional parameters that may be associated with VTE. Methods A retrospective analysis was conducted on 137 pts with newly diagnosed MM between 2017 and 2024. Clinical and laboratory data about disease and inflamamtory burden were collected at diagnosis. SAVED and IMPEDE-VTE scores were calculated. Pts already on anticoagulants at diagnosis (n=7) were excluded. Statistical analysis was performed using GraphPad Prism 10.4.1. Results The median age was 76 years (42–93). 6.5% of pts had an asymptomatic disease. The median follow-up time was 21 months (1-89). VTEs incidence was 6.9% (9/130): 2 cases were registered at diagnosis and 7 during therapy, with a median time to onset of 4 months (0-9). 4 VTE cases occurred in patients on prophylaxis, regardless of the ongoing anticoagulant drug. We observed a correlation between a high SAVED score and VTE events (p=0.032) in IMiDs exposed pts. Conversely, IMPEDE-VTE score did not demonstrate a direct correlation with VTE, likely due to the limited sample size. For the same reason, an association was found between VTE and established risk factors such as IMiD-based therapy, body mass index (BMI) and fractures, but did not reach statistical significance. We performed a univariate analysis among inflammatory and disease activity markers assessed at diagnosis, and we found a strong and significant association between VTE and hypercalcemia (p<0.001). Notably, 86% of patients who presented with hypercalcemia at diagnosis and later developed VTE had high calcium levels at the time of the thrombotic event, even if this occurred well after. No correlation was found between VTE and other CRAB criteria. Conclusion In our experience we evaluated the applicability of the current risk stratification tools for VTE in MM, and found that hypercalcemia at diagnosis may be an independent risk factor for the development of VTE. Prospective studies with larger cohorts are needed to validate this observation

Caratterizzazione citogenetica di una traslocazione sbilanciata 17/21 in JMML

7noneMORERIO C; RAPELLA A; TASSANO E; PANARELLO C; ZECCA M; MASERATI E; PASQUALI F.Morerio, C; Rapella, A; Tassano, E; Panarello, C; Zecca, M; Maserati, Emanuela; Pasquali, Francesc

17Q21-QTER TRYSOMY IS AN INDICATOR OF POOR PROGNOSIS IN ACUTE MYELOGENOUS LEUKAEMIA

A reciprocal translocation (9;11) is often found in acute myeloid leukemia (AML), mostly of the M5a type. We report a case of a child with AML, in whom t(9;11) was observed at diagnosis as the sole structural abnormality, together with trisomies 19 and 21. The diagnosis was AML evolving from a myelodysplastic syndrome (MDS), and the blast morphology was undifferentiated. Chemotherapy failed to induce morphological remission and the patient's condition soon worsened. A subclone appeared and expanded during the course of the disease, with an additional unbalanced translocation (1;17) leading to trisomy of the long arm of chromosome 17 (17q). The data available from the literature on acquired anomalies involving 17q and our observation led us to postulate a specific link between the gain of 17q and complete chemoresistance

17q21-qter trisomy is an indicator of poor prognosis in acute myelogenous leukemia

A reciprocal translocation (9;11) is often found in acute myeloid leukemia (AML), mostly of the M5a type. We report a case of a child with AML, in whom t(9;11) was observed at diagnosis as the sole structural abnormality, together with trisomies 19 and 21. The diagnosis was AML evolving from a myelodysplastic syndrome (MDS), and the blast morphology was undifferentiated. Chemotherapy failed to induce morphological remission and the patient's condition soon worsened. A subclone appeared and expanded during the course of the disease, with an additional unbalanced translocation (1;17) leading to trisomy of the long arm of chromosome 17 (17q). The data available from the literature on acquired anomalies involving 17q and our observation led us to postulate a specific link between the gain of 17q and complete chemoresistance

HCMOGT-1 IS A NOVEL FUSION PARTNER TO PDGFRB IN JUVENILE MYELOMONOCYTIC LEUCEMIA WITH T(5;17)(Q33;P11.2)

PDGFRB, a transmembrane tyrosine kinase receptor for platelet-derived growth factor, is constitutively activated by gene fusion with different partners in myeloproliferative/myelodysplastic disorders with peculiar clinical characteristics. Six alternative partner genes have been described thus far. In this study, we report the molecular cloning of a novel translocation t(5;17)(q33;p11.2) in a case of juvenile myelomonocytic leukemia. The novel partner gene was identified as HCMOGT-1 using 5\u2032-rapid amplification of cDNA ends; fluorescence in situ hybridization and reverse transcriptase-PCR analyses confirmed that the translocation resulted in PDGFRB/HCMOGT-1 fusion. We show that the breakpoint of PDGFRB occurred at the same site of all previously reported PDGFRB translocations