Cryptic t(6;11) KMT2A rearrangement in a pediatric acute myeloid leukemia patient detected by next‐generation sequencing and dual‐fusion FISH analysis

Karyotype (KT) aberrations are important prognostic factors for acute myeloid leukemia (AML); however, around 50% of cases present normal results. Single nucleotide polymorphism array can detect chromosomal gains, losses or uniparental disomy that are invisible to KT, thus improving patients’ risk assessment. However, when both tests are normal, important driver mutations can be detected by the use of next-generation sequencing (NGS). Fourteen adult patients with AML with normal cytogenetics were investigated by NGS for 19 AML-related genes. Every patient presented at least one mutation:DNMT3Ain nine patients;IDH2in six;IDH1in three;NRASandNPM1in two; andTET2,ASXL1,PTPN11, andRUNX1in one patient. No mutations were found inFLT3,KIT,JAK2,CEBPA,GATA2,TP53,BRAF,CBL,KRAS,andWT1genes. Twelve patients (86%) had at least one mutation in genes related with DNA methylation (DNMT3A,IDH1,IDH2,andTET2), which is involved in regulation of gene expression and genomic stability. All patients could be reclassified based on genomic status and nine had their prognosis modified. In summary, NGS offers insights into the molecular pathogenesis and biology of cytogenetically normal AML in Brazilian patients, indicating that the prognosis could be further stratified by different mutation combinations. This study shows a different frequency of mutations in Brazilian population that should be confirmed.

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Co-occurrence of immature T-lymphoblastic lymphoma and acute myeloid leukemia—microenvironment-dependent lineage differentiation derived from a common progenitor?

Journal of Hematopathology ◽

10.1007/s12308-021-00466-4 ◽

2021 ◽

Author(s):

Edit Porpaczy ◽

Wolfgang R. Sperr ◽

Renate Thalhammer ◽

Gerlinde Mitterbauer-Hohendanner ◽

Leonhard Müllauer ◽

...

Keyword(s):

Acute Myeloid Leukemia ◽

Next Generation Sequencing ◽

Myeloid Leukemia ◽

Genetic Alterations ◽

Lymphoblastic Lymphoma ◽

Simultaneous Occurrence ◽

Next Generation ◽

T Lymphoblastic Lymphoma ◽

Generation Sequencing ◽

Acute Myeloid

AbstractMixed phenotype acute leukemia (MPAL) is an uncommon disease characterized by currently only limited knowledge concerning biology, clinical presentation, and treatment outcome. We here describe a most unusual case of simultaneous occurrence of T-lymphoblastic lymphoma in cervical and mediastinal lymph nodes and acute myeloid leukemia in the bone marrow (BM) successfully treated with allogeneic stem cell transplantation (SCT). Although the blasts in both locations showed additional aberrant expression of other lineage markers (even B-cell markers), diagnostic criteria of MPAL were not fulfilled either in the LN or in the BM. We performed next generation sequencing (NGS) with the objective to look for common genetic aberrations in both tissues. Histology, immunohistochemistry, flow cytometry, AML-associated genetic alterations (FLT3, NPM1, KIT D816V, CEPBA), and clonal T-cell receptor β and γ gene rearrangements were performed according to routine diagnostic workflows. Next generation sequencing and Sanger sequencing were additionally performed in BM and LN. Somatic mutation in the EZH2 gene (p.(Arg684Cys)) was detected in the BM by NGS, and the same mutation was found in the LN. Since an identical genetic aberration (EZH2 mutation) was detected in both locations, a common progenitor with regional dependent differentiation may be involved.

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