Acute Myeloid Leukemia Cases Research Articles

Clinical significance of Epstein-Barr Virus detection in the cerebrospinal fluid of patients who underwent hematopoietic stem cell transplantation

Objective: To analyze the detection rate, clinical significance, and prognosis of Epstein-Barr virus (EBV) in the cerebrospinal fluid (CSF) of patients following allogeneic hematopoietic stem cell transplantation. Methods: A retrospective analysis was performed on 1100 patients who underwent the CSF virus test after allogeneic hematopoietic stem cell transplantation in Peking University People's Hospital between January 2017 and June 2022. Among them, 19 patients were screened positive for EBV in their CSF, and their clinical characteristics, treatment, and prognosis were analyzed. Results: Among 19 patients with EBV-positive cerebrospinal fluid, 12 were male and 7 were female, with 5 patients aged <18 years and 12 aged ≥18 years, with a median age of 27 (5-58) years old. There were 7 cases of acute myeloid leukemia, 8 of acute lymphocytic leukemia, 2 of aplastic anemia, 1 of Hodgkin's lymphoma, and 1 of hemophagocytic syndrome. All 19 patients underwent haploid hematopoietic stem cell transplantation, including 1 secondary transplant. Nineteen patients had neurological symptoms (headache, dizziness, convulsions, or seizures), of which 13 had fever. Ten cases showed no abnormalities in cranial imaging examination. Among the 19 patients, 6 were diagnosed with EB virus-related central nervous system diseases, with a median diagnosis time of 50 (22-363) days after transplantation. In 9 (47.3%) patients, EBV was detected in their peripheral blood, and they were treated with intravenous infusion of rituximab (including two patients who underwent lumbar puncture and intrathecal injection of rituximab). After treatment, EBV was not detected in seven patients. Among the 19 patients, 2 died from EBV infection and 2 from other causes. Conclusion: In patients who exhibited central nervous system symptoms after allogeneic hematopoietic stem cell transplantation, EBV should be screened as a potential pathogen. EBV detected in the CSF may indicate an infection; however, it does not confirm the diagnosis.

Nonchromosomal birth defects and risk of childhood acute leukemia: An assessment in 15 000 leukemia cases and 46 000 controls from the Childhood Cancer and Leukemia International Consortium.

Although recent studies have demonstrated associations between nonchromosomal birth defects and several pediatric cancers, less is known about their role on childhood leukemia susceptibility. Using data from the Childhood Cancer and Leukemia International Consortium, we evaluated associations between nonchromosomal birth defects and childhood leukemia. Pooling consortium data from 18 questionnaire-based and three registry-based case-control studies across 13 countries, we used multivariable logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between a spectrum of birth defects and leukemia. Our analyses included acute lymphoblastic leukemia (ALL, n = 13 115) and acute myeloid leukemia (AML, n = 2120) cases, along with 46 172 controls. We used the false discovery rate to account for multiple comparisons. In the questionnaire-based studies, the prevalence of birth defects was 5% among cases vs 4% in controls, whereas, in the registry-based studies, the prevalence was 11% among cases vs 7% in controls. In pooled adjusted analyses, there were several notable associations, including (1) digestive system defects and ALL (OR = 2.70, 95% CI: 1.46-4.98); (2) congenital anomalies of the heart and circulatory system and AML (OR = 2.86, 95% CI: 1.81-4.52) and (3) nervous system defects and AML (OR = 4.23, 95% CI: 1.50-11.89). Effect sizes were generally larger in registry-based studies. Overall, our results could point to novel genetic and environmental factors associated with birth defects that could also increase leukemia susceptibility. Additionally, differences between questionnaire- and registry-based studies point to the importance of complementary sources of birth defect phenotype data when exploring these associations.

Akut Miyeloid Lösemide FLT3 Mutasyonlarının Araştırılması: Hasta Sonuçları ve Tedavi Stratejileri Üzerine Tek Merkezli Gerçek Yaşam Verisi

Acute Myeloid Leukemia (AML) is a complex hematological malignancy with considerable genetic heterogeneity. Fms-like tyrosine kinase 3 (FLT3) mutations are associated with poor prognosis and occur in nearly 30% of AML cases. This study delves into the prevalence of FLT3 mutations, their impact on clinical outcomes, and the efficacy of various treatment approaches in a cohort of AML patients. We examined 157 de novo non-acute promyelocytic leukemia AML patients aged 20-95 years, screening for FLT3-ITD and FLT3-TKD mutations. We tailored chemotherapy based on age, ECOG performance status, and FLT3 mutation presence. Our research revealed that 27.3% of patients harbored FLT3 mutations, with 65% FLT3-ITD and 35% FLT3-TKD mutations. Those with FLT3 mutations exhibited higher mortality rates compared to patients without mutations. Age, FLT3 mutation status, and relapsed/refractory disease emerged as independent risk factors for mortality. Patients treated with midostaurin faced a lower mortality risk than those administered sorafenib. This study underscores the significance of FLT3 mutations in AML, their influence on clinical outcomes, and the advantages of targeted therapies. Our findings stress the urgency for further investigation aimed at enhancing the prognosis for AML patients with FLT3 mutations.

Early occurrence of acute myelomonocytic leukemia (M4/M5) after liver transplantation: a case report

IntroductionAcute myeloid leukemia is a rare event in post-liver-transplantation recipients. In the present report, we described a case of extramedullary acute myeloid leukemia, M4/M5 subtype, following orthotopic liver transplant.Case presentationThe patient was a 50-year-old Iranian woman who underwent orthotopic liver transplant due to hepatitis B-related cirrhosis (Child C, MELD (model for end-stage liver disease score) = 22). Orthotopic liver transplant was performed using the piggy back technique in January 2022. Induction immunosuppressive therapy was 1 gm methylprednisolone for 3 days followed by a triple maintenance immunosuppressive regimen including mycophenolate mofetil, prednisolone, and tacrolimus. About 5 months after orthotopic liver transplant in June 2022, the patient presented with leukocytosis, with white blood cell count of 99.4 × 103/µl, and physical examination revealed only cervical lymphadenopathy. Biopsy of cervical lymph nodes showed a myeloid tumor. She was immediately hospitalized. Eight hours after hospitalization, the patient gradually developed lethargy and decreased O2 saturation to approximately 89%. Flow cytometry demonstrated the markers of a myelomonocytic acute myeloid leukemia (M4/M5). Cytoreduction was immediately started by intensive leukopheresis followed by induction therapy. Because of a septic complication during the induction therapy, further chemotherapy was discontinued and broad-spectrum antibiotics and antifungal treatments started. Unfortunately, our patient died of severe septic shock 42 days after hospitalization.ConclusionAcute myeloid leukemia is a rare phenomenon after liver transplantation, and it can follow a rapidly fatal clinical course.

FUS-ERG induces late-onset azacitidine resistance in acute myeloid leukaemia cells

FUS-ERG is a chimeric gene with a poor prognosis, found in myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML). It remains unclear whether DNA hypomethylating agents, including azacitidine (Aza), are effective in FUS-ERG-harbouring AML and how FUS-ERG induces chemoresistance. Stable Ba/F3 transfectants with FUS-ERG were repeatedly exposed to Aza for 7 days of treatment and at 21-day intervals to investigate Aza sensitivity. Stable FUS-ERG transfectants acquired resistance acquired resistance after three courses of Aza exposure. RNA sequencing (RNA-seq) was performed when Aza susceptibility began to change; genes with altered expression or transcript variants were identified. Molecular signatures of these genes were analysed using gene ontology. RNA-seq analyses identified 74 upregulated and 320 downregulated genes involved in cell motility, cytokine production, and kinase activity. Additionally, 1321 genes with altered transcript variants were identified, revealing their involvement in chromatin organisation. In a clinical case of AML with FUS-ERG, we compared whole-genome alterations between the initial MDS diagnosis and AML recurrence after Aza treatment. Genes with non-synonymous or near mutations in transcription regulatory areas (TRAs), additionally detected in AML recurrence, were collated with the gene list from RNA-seq to identify genes involved in acquiring Aza resistance in the presence of FUS-ERG. Whole-genome sequencing of clinical specimens identified 29 genes with non-synonymous mutations, including BCOR, and 48 genes located within 20 kb of 54 TRA mutations in AML recurrence. These genes were involved in chromatin organisation and included NCOR2 as an overlapping gene with RNA-seq data. Transcription regulators involved in mutated TRAs were skewed and included RCOR1 in AML recurrence. We tested the efficacy of BH3 mimetics, including venetoclax and S63845, in primary Aza-resistant AML cells treated with FUS-ERG. Primary FUS-ERG-harbouring AML cells acquiring Aza resistance affected the myeloid cell leukaemia-1 (MCL1) inhibitor S63845 but not while using venetoclax, despite no mutations in BCL2. FUS-ERG promoted Aza resistance after several treatments. The disturbance of chromatin organisation might induce this by co-repressors, including BCOR, NCOR2, and RCOR1. MCL1 inhibition could partially overcome Aza resistance in FUS-ERG-harbouring AML cells.

17p Deletion in Patients with De Novo Acute Myeloid Leukemia and their Clinico-Haematologic Features

Objective: To determine the frequency of 17p deletion in patients with Acute Myeloid Leukemia and their clinical-hematologic features using fluorescence in situ hybridization.&#x0D; Study Design: Cross-sectional study.&#x0D; Place &amp; Duration of Study: Department of Hematology, Armed Forces Institute of Pathology, Rawalpindi Pakistan, from Dec 2018 to Dec 2019.&#x0D; Methodology: All diagnosed cases of Acute Myeloid Leukemia of all ages and genders were included. Interphase FISH testing was performed using blood or bone marrow specimens using 10μL of the Meta systems XL p53 probe, and a total of 500 nuclei per assay were analyzed using a fluorescent microscope. Del 17p positivity and negativity were noted. Clinico-haematologic features of the patients with and without del 17p were also noted.&#x0D; Results: In our targeted population of 84 patients, there were 25(29.8%) females and 59(70.2%) males. The mean age of presentation was 36.3±1.6 years. The mean total leucocyte count(TLC)was 31.2±4.2×109/L, and the mean platelet count was 69.3±4.5×109/L. Del 17p was detected in a total of 8(9.5%) patients. The median age of patients with del 17p at diagnosis was 33 years, the mean TLC was 12.32±10.36x109/L, and the mean platelet count was 80±26.73*109/L. Prominent clinical features among patients with del 17p included fever and pallor.&#x0D; Conclusion: Our study suggests a relatively low frequency of del 17p in AML (9.5%), which is consistent with international data.

ß-catenin expression in myelodysplastic syndromes and myeloproliferative neoplasms in bone marrow, in relation to CD34 and CD117 status

Aims: The activation of the Wnt/ ß-catenin signaling pathway has been demonstrated to play a crucial role in the development of myeloid neoplasms. In addition to CD34, which has been used until now in the diagnosis and staging of clonal hematopoietic diseases, Myelodysplastic Syndromes (MDS) and Myeloproliferative Neoplasms (MPN), CD117, which has found its place in hematopoietic diseases, also provides significant benefits in these respects. In this study, we evaluated the immunohistochemical presence and utility of ß-catenin in blasts relative to other markers, as the inhibition of ß-catenin activity may be an attractive therapeutic approach Methods: By retrospectively analyzing bone marrow samples with ß-catenin immune marker, we determined the staining rates, intensities, and patterns of 30 MDS, 29 MPN cases and 30 normal bone marrow controls, in comparison to the efficacy of the the well-known CD34 and CD117. We statistically interpreted the correlation between them. Results: Based on the findings, ß-catenin, which has recently been used in hematopoietic diseases and is said to have a high efficacy in acute myeloid leukemia (AML) cases, was not immunohistochemically detectable in our study. As expected, CD34 and CD117 immun markers exhibited significant blast staining. MPN cases were more prone to staining with CD117. Conclusion: CD34 continues to be the most reliable marker for identifying blasts for diagnosing and grading bone marrow neoplasms while CD117 may have a supportive role in this process. Further investigation is required to ascertain the true effectiveness of ß-catenin, a molecule that has demonstrated encouraging potential in the context of AML.

Application of the International Consensus Classification and World Health Organization 5th edition classification to a series of myeloid neoplasms.

Two new classifications of myeloid neoplasms have recently been published: the International Consensus Classification (ICC) and the 5th edition of the World Health Organization classification (WHO5). We sought to examine the real-world impact of dueling classifications on patient diagnoses. Our institutional pathology database was searched, and 237 specimens with a diagnosis of myeloid neoplasia were randomly selected. For each case, a classification based on the WHO5 and the ICC was assigned. The WHO5 and ICC diagnoses were compared to determine their degree of concordance. After applying the WHO5 and ICC diagnostic criteria, 134 (56.5%) cases were classified as concordant, 63 (26.6%) cases had terminological differences, 37 (15.6%) cases had minor diagnostic discrepancies, and 3 (1.3%) cases had major diagnostic discrepancies. Cases with minor diagnostic discrepancies included 25 cases of myelodysplastic syndrome (MDS), 10 cases of acute myeloid leukemia (AML), and 2 cases of myeloid precursor lesions. Cases with major diagnostic discrepancies included 2 cases that were diagnosed as MDS, not otherwise specified (NOS), according to the ICC but classified as AML with NPM1 alteration and AML with RBM15::MRTFA according to the WHO5 and 1 case that was characterized as chronic myelomonocytic leukemia according to the ICC and as AML with NPM1 alteration according to the WHO5. This study confirms that a majority of cases are classified similarly using the 2 systems. Given the overall similarity of the systems, future harmonization of the classifications should be pursued to avoid confusion and multiple diagnoses.

Polymorphisms in the NADPH quinone dehydrogenase 1 (NQ01) gene in Saudi patients with acute myeloid leukemia

Acute myeloid leukemia (AML) is a hematological malignancy that contains hereditary subgroups. AML can arise as a result of a previous myeloid malignancy. AML's molecular pathogenesis is not yet complete. NADPH quinone dehydrogenase 1 (NQ01), which is linked to AML, is one of a few handfuls of genes that have a role in AML pathogenesis. The goal of this study was to look at the roles of C609T and C465T polymorphisms in the NQ01 gene in the development of AML in Saudis. In this experimental study, 100 AML patients and 100 healthy controls were chosen. For the C609T and C465T PCR products, restriction enzymes were utilized in this study. AML cases and controls were investigated for genotype and allele frequencies. The average age of AML patients and control subjects was 39.9 ± 12.06 years. AML patients were 61% male and 39% female, while controls were 54% male and 46% female. The C609T and C465T polymorphisms in the NQ01 gene were not linked with any of the genotypes (p > 0.05). According to the findings of this investigation, the C609T and C465T polymorphisms play no effect in AML patients in Saudi Arabia.

Acute myeloid leukemia with LRRFIP1::FGFR1 rearrangement and a complex karyotype

We report a case of a 20-year-old man who presented with splenomegaly, hyperleukocytosis, anemia, and thrombocytopenia. A diagnosis of acute myeloid leukemia (AML) with LRRFIP1::FGFR1 rearrangement with complex karyotype was determined. Chromosome analysis showed a male karyotype: 46,XY,i(1)(q10),t(2;8)(q37;p11.2),der(5)t(1;5) (p22;q13)[17]46,XY[3]. Fluorescence in situ hybridization (FISH) analysis using the Cytocell FGFR1 break apart/amplification probe detected FGFR1 rearrangement with t(2:8) in 126/200 cells analyzed. Other FISH probes including 1p36/ 1q25 probes, del(5q) deletion probe, TLX3 break apart probe, and PDGFRB break apart probe were also utilized to confirm the other karyotypic abnormalities. Next-generation sequencing (NGS) SureSelectXT Custom DNA Target Somatic Detection detected RUNX1 gene mutation. NGS Archer FusionPlex (RNA) confirmed the LRRFIP1::FGFR1 rearrangement. This is the second reported case of AML with LRRFIP1::FGFR1 rearrangement and the first with a complex karyotype.

An integrative computational approach for the identification of dual inhibitors of isocitrate dehydrogenase 1 and 2 from phytocompounds of Phyllantus amarus

Genetic alterations of the genes encoding the isocitrate dehydrogenase (IDH) enzymes have been identified in about 20% of acute myeloid leukemia (AML) cases as well as many other forms of cancers. Notable among these alterations are the neomorphic IDH1_R132H and IDH2_R140Q mutations which lead to the production of an oncometabolite. Hence, their inhibition is widely considered a therapeutic strategy in the treatment of many cancers. While many inhibitors of the mutant enzymes have been developed, an inhibitor that is capable of co-inhibiting both enzymes are currently lacking while drug resistance has also limited the clinical usage of previously identified mono inhibitors. Consequently, this study employed molecular modeling approaches, such as molecular docking, molecular mechanics generalized Born Surface area (MM/GBSA), molecular dynamics (MD) simulation, and density functional theory (DFT) analysis to identify potential dual inhibitors of the previously mentioned mutant IDH1/2 from the phytocompounds of Phyllantus amarus. Of the 31 phytocompounds identified, 20 showed good binding affinities for both IDH1 _R132H and IDH2 _R140Q (ranging from −5.2 Kca/mol to −9.6 Kcal/mol) and had desirable pharmacokinetic properties. However, ellagic acid and pinoresinol possessed better pharmacokinetic properties, rendering suitable hits. Investigation of the behavior of the IDH1_R132H and IDH2_R140Q complexes with ellagic acid and pinoresinol via the RMSD, RMSF, and contact map analyses showed that all the complexes-maintained stability throughout the simulation time. Ultimately, ellagic acid and pinoresinol were identified as promising hits for the development of IDH1_R132H and IDH2_R140Q dual inhibitors. However, further experimental studies are needed to confirm their potential as therapies. Communicated by Ramaswamy H. Sarma

The curious case of IDH mutant acute myeloid leukaemia: biochemistry and therapeutic approaches.

Of the many genetic alterations that occur in cancer, relatively few have proven to be suitable for the development of targeted therapies. Mutations in isocitrate dehydrogenase (IDH) 1 and -2 increase the capacity of cancer cells to produce a normally scarce metabolite, D-2-hydroxyglutarate (2-HG), by several orders of magnitude. The discovery of the unusual biochemistry of IDH mutations spurred a flurry of activity that revealed 2-HG as an 'oncometabolite' with pleiotropic effects in malignant cells and consequences for anti-tumour immunity. Over the next decade, we learned that 2-HG dysregulates a wide array of molecular pathways, among them a large family of dioxygenases that utilise the closely related metabolite α-ketoglutarate (α-KG) as an essential co-substrate. 2-HG not only contributes to malignant transformation, but some cancer cells become addicted to it and sensitive to inhibitors that block its synthesis. Moreover, high 2-HG levels and loss of wild-type IDH1 or IDH2 activity gives rise to synthetic lethal vulnerabilities. Herein, we review the biology of IDH mutations with a particular focus on acute myeloid leukaemia (AML), an aggressive disease where selective targeting of IDH-mutant cells is showing significant promise.

Prevalence of Gene Rearrangement by Multiplex PCR in De Novo Acute Myeloid Leukemia in Adult Iraqi Patients.

Gene rearrangements of acute myeloid leukemia (AML) play a significant role in categorizing patients and provide valuable information about prognosis and treatment choices. However, in Iraq, the prevalence and prognostic significance of gene rearrangements in AML have not been previously examined. This study utilized a multiplex reverse transcription real-time PCR (RT-qPCR) system to identify gene rearrangements in a group of 115 adult patients from Iraq who had been diagnosed with De Novo AML. The diagnosis of AML was confirmed through blood film and flow cytometry. The ethical committee of the College of Medicine at the University of Baghdad provided approval for this research study. In this study, 66.1% of the patients diagnosed with acute myeloid leukemia (AML) exhibited distinct genetic abnormalities. Among these abnormalities, the most frequent was the rearrangement involving the KMT2A gene, observed in 19.9% of the patients. The risk stratification analysis revealed that 40% of the patients were classified as having a favorable risk, 4.3% as intermediate risk, and 25.2% as adverse risk. A subtype of AML known as core-binding factor (CBF) AML was identified in 21.7% of the cases, with 84% of these patients achieving complete remission. The NPM-RARA gene rearrangement, found in 43% of acute promyelocytic leukemia (APL) cases, was associated with a 71% complete remission rate. Among patients with KMT2A rearrangement, which accounted for 19.9% of all AML cases, the MLL-AF10 rearrangement was the most common, although only one patient with KMT2A rearrangement achieved complete remission. Furthermore, the analysis of demographic data revealed a significant association between increased risk and advanced age, presence of comorbidities, and FAB classification (M0 subtype). The prevalence of genetic rearrangements in Iraqi De Novo AML patients is higher than the global trend, highlighting the importance of genetic characterization in risk assessment and treatment decisions.

Phenotypic clues that predict underlying cytogenetic/genetic abnormalities in myeloid malignancies: A contemporary review.

Precise subclassification of myeloid malignancies per the World Health Organization (WHO) classification system and the International Consensus Classification of Myeloid Neoplasms and Acute Leukaemias (ICC) requires investigation and documentation of the presence of cytogenetic and/or molecular genetic changes. These ancillary studies not only help in diagnosis, but also the prognosis of disease; however, they take time to be completed. In contrast, morphological evaluation of material from the blood and bone marrow specimens of cases where myeloid malignancies are suspected is usually completed quickly. Cytomorphological assessment may predict genetic changes and can be helpful in triaging acuity. This is especially true in haematological emergencies such as acute promyelocytic leukaemia (APL), where prompt APL-specific therapy can be life changing. Similarly, some morphological clues may help identify core binding factor leukaemias where a diagnosis of acute myeloid leukaemia (AML) could be rendered without reaching the 20% blast cutoff with immediate treatment-decision implications, or even a subset of cases of AML with FLT3 ITD/NPM1 mutation(s) which show characteristic features. Even though FISH/cytogenetics and/or PCR are still required for establishing the final diagnosis, evaluation for the presence of specific cytomorphological features that help predict genetic changes can be a useful tool to help guide early therapy.

Iron-laden blasts in refractory acute myeloid leukemia

We report a case of refractory acute myeloid leukemia with DEK-NUP214 rearrangement showing circulating monocytic blasts with abundant green cytoplasmic granules on the Wright-Giemsa stain. The granules were strongly positive for Perls’ Prussian blue, consistent with hemosiderin deposits. This previously unreported finding is suggestive of siderophage activity by leukemic blasts, likely associated with monocytic differentiation.

Leukemic Transformation of Longstanding Essential Thrombocythemia

Acute Myeloid Leukemia (AML) represents only 1% of all cancers, despite being the most frequent type of leukemia [1]. Multiple genetic pathways are associated with AML, causing various changes in genetic transcription, apoptosis, chromatin remodeling, and protein levels. One such pathway, the JAK-STAT pathway, governs cellular proliferation, differentiation, and apoptosis, and is linked to both AML and myeloproliferative neoplasms due to mutations [2]. The JAK V617F mutation is the most common mutation in this pathway, occurring in about 50% of Essential Thrombocythemia (ET) patients, as described in this report [2]. While rare, transformation of Essential Thrombocythemia (ET) to AML occurs in 1-4% of cases [3]. This report presents a case of AML in a 76-year-old male with a medical history of ET. Following an abnormal peripheral blood smear, bone marrow biopsy confirmed the diagnosis. The current report aims to emphasize the significance of regular screening and monitoring for patients with long-standing Essential Thrombocythemia (ET), especially those under suppressive therapy. The transformation of ET to acute leukemia is associated with an unfavorable prognosis, underscoring the importance of early diagnosis. Therefore, this case serves to draw attention to the criticality of timely intervention through routine follow-up to achieve optimal outcomes for patients with ET.

Influenza A (H1N1) virus induced long-term remission in a refractory acute myeloid leukaemia.

You et al. present an extraordinary case of a refractory acute myeloid leukaemia (AML) patient who achieved long-term complete remission after infection with Influenza A. Using mouse models, the researchers examined the underlying immunological mechanisms and discovered a decrease in leukaemia proliferation and improved survival in Influenza-A virus-infected mice. These results indicate the potential therapeutic relevance of Influenza A in the treatment of haematological cancers. Commentary on: You et al. Influenza A (H1N1) virus induced long-term remission in a refractory acute myeloid leukemia. Br J Haematol 2023;202:745-748.

Acute myeloid leukemia relapsing in the vitreous

A 47-year-old female was a known case of acute myeloid leukemia (AML-M5) and presented with a diminution of vision in the right eye (OD) for two weeks. Examination revealed pigmented cells in the anterior vitreous of both eyes with vitritis OD. She was further treated with vitreous biopsy and diagnostic vitrectomy under air OD. The cytology examination of the vitreous biopsy revealed infiltration with myeloblasts confirming the diagnosis of extramedullary relapse of AML inside the vitreous. She was further treated with intrathecal chemotherapy. She did not have any further relapse till two years after her last follow-up. This case highlights a rare location of extramedullary relapse of AML inside the vitreous which has not been reported as per the literature search. Moreover, diagnostic vitrectomy under air helped in getting more undiluted vitreous fluid, which also helped in confirming the relapse with cytology examination.

CBFA2T3::GLIS2-positive acute leukemia with RAM and mixed T/megakaryocytic phenotype.

Herein, we present a rare case of acute myeloid leukemia (AML) with CBFA2T3-rearrangement and the expression of megakaryocytic and lymphoid markers, highlighting the need for a high suspicion index in differential diagnosis and applying adequate workup to avoid misdiagnosing this entity. CBFA2T3::GLIS2-positive AML is primarily found in infants with non-down syndrome acute megakaryoblastic leukemia (non-DSAMKL). Flow cytometry immunophenotyping plays an important role in recognizing the unique immunophenotype of bright CD56 expression with dim/negative expression of HLA-DR, CD38, and CD45 termed the RAM immunophenotype in this entity. Still, CBFA2T3::GLIS2-positive acute leukemia with T/megakaryocytic markers could be misdiagnosed as T-lymphoblastic leukemia/lymphoma, early T-cell precursor acute lymphoblasticleukemia/lymphoma, NK lymphoblastic leukemia, AML with minimal differentiation, or AML with myelodysplasia-related changes.

Genomic breakpoint-specific monitoring of measurable residual disease in pediatric non-standard-risk acute myeloid leukemia.

Pediatric acute myeloid leukemia (AML) is a highly heterogeneous disease making standardized measurable residual disease (MRD) assessment challenging. Currently, patient-specific DNA-based assays are only rarely applied for MRD assessment in pediatric AML. We tested whether quantification of genomic breakpoint-specific sequences via quantitative polymerase chain reaction (gDNA-PCR) provides a reliable means of MRD quantification in children with non-standardrisk AML and compared its results to those obtained with state-of-the-art ten-color flow cytometry (FCM). Breakpointspecific gDNA-PCR assays were established according to Euro-MRD consortium guidelines. FCM-MRD assessment was performed according to the European Leukemia Network guidelines with adaptations for pediatric AML. Of 77 consecutively recruited non-standard-risk pediatric AML cases, 49 (64%) carried a chromosomal translocation potentially suitable for MRD quantification. Genomic breakpoint analysis returned a specific DNA sequence in 100% (41/41) of the cases submitted for investigation. MRD levels were evaluated using gDNA-PCR in 243 follow-up samples from 36 patients, achieving a quantitative range of at least 10-4 in 231/243 (95%) of samples. Comparing gDNA-PCR with FCM-MRD data for 183 bone marrow follow-up samples at various therapy timepoints showed a high concordance of 90.2%, considering a cut-off of ≥0.1%. Both methodologies outperformed morphological assessment. We conclude that MRD monitoring by gDNA-PCR is feasible in pediatric AML with traceable genetic rearrangements and correlates well with FCM-MRD in the currently applied clinically relevant range, while being more sensitive below that. The methodology should be evaluated in larger cohorts to pave the way for clinical application.