Clonal Dynamics and Relapse Risk Revealed by High-Sensitivity FLT3-Internal Tandem Duplication Detection in Acute Myeloid Leukemia.

The ability to detect low-level disease is key to our understanding of clonal heterogeneity in acute myeloid leukemia (AML) and residual disease that elude conventional assays and seed relapse. We developed a high-sensitivity next-generation sequencing (HS-NGS) clinical assay, able to reliably detect low levels (1 × 10) of FLT3-ITD, a frequent, therapeutically targetable and prognostically relevant mutation in AML. By applying this assay to 289 longitudinal samples from 62 patients at initial diagnosis and/or clinical follow-up (mean follow-up of 22 months), we reveal the frequent occurrence of FLT3-ITD subclones at diagnosis and demonstrate a significantly decreased relapse risk when FLT3-ITD is cleared after induction or thereafter.

Side scatter ratio of the CD105-positive and CD105-negative red blood cell fractions is useful for the detection of low-grade myelodysplastic neoplasms by flow cytometry.

Objectives: We assessed the utility of red blood cell (RBC) CD105 and side scatter (SSC) parameters by flow cytometry for the detection of low-grade myelodysplastic neoplasms (MDS) in bone marrow specimens.

Methods: Ten RBC parameters incorporating CD105 or SSC combined with the Meyerson-Alayed scoring system (MASS) metrics were retrospectively evaluated by flow cytometry for utility in detecting low-grade MDS (n = 56) compared with cytopenic controls (n = 86).

Results: Myelodysplastic neoplasms were associated with 7 of the RBC parameters in univariate analysis.

Philadelphia chromosome-positive T-cell acute lymphoblastic leukemia: a case report.

Philadelphia chromosome-positive (Ph+) T-cell acute lymphoblastic leukemia (T-ALL) is a rare and aggressive type of acute leukemia. The Philadelphia chromosome is the hallmark of chronic myeloid leukemia (CML). The differentiation between Ph+ T-ALL and T-cell lymphoblastic crisis of CML may be problematic in some cases.

IGJ and SPATS2L immunohistochemistry sensitively and specifically identify BCR::ABL1+ and BCR::ABL1-like B-acute lymphoblastic leukaemia.

Therapeutic management and prognostication for patients with B-acute lymphoblastic leukaemia (B-ALL) require appropriate disease subclassification. BCR::ABL1-like B-ALL is unique in that it is defined by a gene expression profile similar to BCR::ABL1+ B-ALL rather than a unifying recurrent translocation. Current molecular/cytogenetic techniques to identify this subtype are expensive, not widely accessible, have long turnaround times and/or require an adequate liquid biopsy.

KAT6A::EP300 fusion in congenital myeloid sarcoma: Yet another novel molecular marker indicating spontaneous remission?: A case report.

Rationale: Acute myeloid leukemia (AML)/myeloid sarcoma (MS) is risk-stratified based on cytogenetics. Although most congenital AML/MS have a dismal prognosis, certain genetic variants such as t (8, 16) [KAT6A::cAMP response element-binding protein (CREB) - binding protein fusion] and more recently t (8, 22) [KAT6A::EP300 fusion] have shown spontaneous remissions. KAT6A located on chromosome 8p11 encodes KAT6A protein, a histone/lysine acetyltransferase enzyme.

Aggressive Lymphoplasmacytic Neoplasm With an Unusual In-frame Deletion of Associated With and Mutations and Complex Karyotype.

Lymphoplasmacytic lymphoma often needs to be differentiated from other B-cell lymphomas with plasmacytic differentiation, especially marginal zone cell lymphoma. Molecular detection of p.L265P hotspot mutation supports the diagnosis of lymphoplasmacytic lymphoma since it is seen in about 90% of such lymphoma, which is much higher than other B-cell lymphomas.

Mucin 4 protein is expressed in B-acute lymphoblastic leukemia and is restricted to BCR::ABL1-positive and BCR::ABL-like subtypes.

Mucin 4 (MUC4) is a transmembrane mucin that, like most mucins, is not expressed in normal hematopoietic cells, but little is known about its expression in malignant hematopoiesis. B-acute lymphoblastic leukemia (B-ALL) consists of genetically distinct disease subtypes with similarities and differences in gene expression most frequently studied at the mRNA level, which is less amenable to widespread routine clinical use. Here, we demonstrate using immunohistochemistry (IHC) that MUC4 protein is expressed in less than 10% of B-ALL, with expression restricted to BCR::ABL1+ and BCR::ABL1-like (CRLF2 rearranged) subtypes of B-ALL (4/13, 31%).

HSF1 is a driver of leukemia stem cell self-renewal in acute myeloid leukemia.

Acute myeloid leukemia (AML) is maintained by self-renewing leukemic stem cells (LSCs). A fundamental problem in treating AML is that conventional therapy fails to eliminate LSCs, which can reinitiate leukemia. Heat shock transcription factor 1 (HSF1), a central regulator of the stress response, has emerged as an important target in cancer therapy.

Vascular surgery patients with elevated neutrophil-to-lymphocyte ratios have downregulated neutrophil complement RNA expression.

Elevated neutrophil-to-lymphocyte ratio (NLR) in patients who undergo elective vascular surgery (EVS) have increased mortality independent of perioperative surgical outcome. To understand why high NLR is associated with higher mortality, we investigated neutrophil and lymphocyte transcriptome expression in patients undergoing EVS. Blood samples were collected from patients undergoing EVS and healthy donors for NLR calculation.

Machine Learning to Predict Risk of Relapse Using Cytologic Image Markers in Patients With Acute Myeloid Leukemia Posthematopoietic Cell Transplantation.

Purpose: Allogenic hematopoietic stem-cell transplant (HCT) is a curative therapy for acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS). Relapse post-HCT is the most common cause of treatment failure and is associated with a poor prognosis. Pathologist-based visual assessment of aspirate images and the manual myeloblast counting have shown to be predictive of relapse post-HCT.

ALK-positive Large B-Cell Lymphoma Presenting as a Circumscribed Breast Mass with Germinal Center Immunophenotype.

We report a rare case of ALK-positive large B cell lymphoma which initially presented as a circumscribed breast mass in a young woman mimicking fibroadenoma. The lymphoma demonstrated typical immunoblastic morphology with monomorphic round nuclei and prominent central nucleoli. Immunophenotypically, the lymphoma was positive for MUM1,CD138, BOB1, OCT2, PAX5 (focal), CD4, and was negative for CD20, CD79a and all other T cell antigens.

Decreased CD177 neutrophils in myeloid neoplasms is associated with NPM1, RUNX1, TET2, and U2AF1 S34F mutations.

A decreased percentage of CD177 neutrophils is frequently present in MDS and AML and is a useful flow cytometry (FCM) marker for the identification of MDS. The underlying mechanism leading to the low percentage of CD177 neutrophils in MDS has not been explained. The aim of this study was to identify whether specific somatic mutations in myeloid neoplasms are associated with the low percentage of CD177 neutrophils.

Initial assessment of α-synuclein structure in platelets.

Over the last few years data from our group have indicated that α-synuclein is important in development of immune cells as well as potentially erythrocytes and platelets. The latter is important since this protein may work as negative regulator of granule release. Thus, we sought to begin to understand the structure of this protein in platelets.

Flow Cytometric Findings in Clonal Cytopenia of Undetermined Significance.

Objectives: To examine flow cytometric (FCM) findings in clonal cytopenia of undetermined significance (CCUS) in relation to variant allele fraction (VAF) and mutation risk.

Methods: Nine FCM parameters, including 5 FCM metrics (Meyerson-Alayed scoring scheme [MASS] parameters) we previously used to identify myelodysplastic syndromes (MDS), were compared among 96 CCUS samples, 100 low-grade MDS samples and 100 samples from patients without somatic alterations (controls).

Results: FCM findings did not differ between CCUS samples with less than 20% VAF and controls.

Clinical Utility of Targeted Next-Generation Sequencing in the Evaluation of Low-Grade Lymphoproliferative Disorders.

Objectives: We investigated the usefulness of a custom-designed 31-gene next-generation sequencing (NGS) panel implemented on a routine basis for the evaluation of low-grade lymphoproliferative disorders (LPDs).

Methods: In total, 147 blood, bone marrow, and tissue specimens were sequenced, including 81% B-cell, 15% T-cell, and 3% natural killer (NK)-cell neoplasms.

Results: Of the cases, 92 (63%) of 147 displayed at least one pathogenic variant while 41 (28%) of 147 had two or more.

Clonal cytopenia of undetermined significance (CCUS) with dysplasia is enriched for MDS-type molecular findings compared to CCUS without dysplasia.

Objectives: Although morphologic dysplasia is not typically considered a feature of CCUS, we have consistently observed low-level bone marrow (BM) dysplasia among CCUS patients. We sought to determine whether sub-diagnostic BM dysplasia in CCUS patients is associated with other clinico-pathologic findings of myelodysplastic syndrome (MDS).

Methods: We identified 49 CCUS patients, 25 with sub-diagnostic dysplasia (CCUS-D), and 24 having no dysplasia (CCUS-ND).

CD177 Enhances the Detection of Myelodysplastic Syndrome by Flow Cytometry.

Objectives: Previously we demonstrated that a decreased percentage of CD177-positive granulocytes detected by flow cytometry (FCM) was associated with myelodysplastic syndrome (MDS). Here we expand on those findings to more rigorously evaluate the utility of CD177 for the detection of MDS.

Methods: Two hundred patient samples (100 MDS and 100 controls) were evaluated for granulocyte expression of CD177 and 11 other flow cytometric parameters known to be associated with MDS.

The whole-genome landscape of Burkitt lymphoma subtypes.

Burkitt lymphoma (BL) is an aggressive, MYC-driven lymphoma comprising 3 distinct clinical subtypes: sporadic BLs that occur worldwide, endemic BLs that occur predominantly in sub-Saharan Africa, and immunodeficiency-associated BLs that occur primarily in the setting of HIV. In this study, we comprehensively delineated the genomic basis of BL through whole-genome sequencing (WGS) of 101 tumors representing all 3 subtypes of BL to identify 72 driver genes. These data were additionally informed by CRISPR screens in BL cell lines to functionally annotate the role of oncogenic drivers.