Search Results (4)

Acute myeloid leukemia (AML) with RUNX1::RUNX1T1 fusion is well known to often demonstrate aberrant upregulation of CD19 expression. We studied the clinicopathologic and genetic features of 16 cases of AML with various RUNX1 lesions, including mutations, copy number gains, and translocations other than fusions with RUNX1T1. Most of these cases were classified as AML-myelodysplasia-related or AML-post-cytotoxic therapy based on the cytogenetic and molecular work-up. These neoplasms showed partial expression of one or more B-cell antigens by flow cytometry and/or immunohistochemistry, fulfilling the criteria for mixed-phenotype acute leukemia (MPAL)-B/myeloid (i.e., ≥20% blasts expressing B and myeloid lineage antigens) in most cases. These findings suggest that AML cases with RUNX1 lesions including mutations, copy number gains, and translocations other than RUNX1T1 fusion, also commonly express B-cell markers, imparting a “mixed-lineage-like” immunophenotype in cases of AML that otherwise fulfill the criteria for other defined subtypes. We present these cases as to caution regarding this potential diagnostic pitfall and favor a diagnosis of AML with RUNX1 lesion(s) in the setting of a case of AML with myeloid/B-cell antigen expression, a history of myelodysplasia or cytotoxic therapy, the demonstration of pDC differentiation by flow cytometry (generally associated with the presence of a RUNX1 mutation), and the presence of a RUNX1 lesion (mutation, copy number gain, and/or translocation exclusive of a rearrangement with RUNX1T1). Full article

Background/Objectives: Myeloid neoplasms are the most common secondary blood cancer in B-cell non-Hodgkin lymphoma (BNHL) patients treated with cytotoxic therapies. We aimed to characterize the genetic and clinicopathologic features of myeloid neoplasms arising after B-cell non-Hodgkin lymphoma (MN-BNHL) by comparing their features with myeloid neoplasms developing after solid cancer (MN-SC). Methods: We retrospectively analyzed the clinicopathologic and genetic data of myeloid neoplasm patients diagnosed between 2008 and 2023, categorized as MN-BNHL or MN-SC. Further NGS analysis was performed on available bone marrow samples with missing genetic data. The genetic profiles of myeloid neoplasms between BNHL and solid cancer groups were compared. Results: Sixteen patients developed MN-BNHL. Among the 11 MN-BNHL patients undergoing NGS, all harbored tier 1 mutations. PPM1D mutations (PPM1Dms) were most frequent (73%), followed by DNMT3A (46%) and TP53 (36%). PPM1Dms were significantly more prevalent than in MN-SC (n = 21), where TP53 mutations were most common (64%) (p < 0.001). PPM1Dms often co-occurred with DNMT3A. They were associated with prior radioimmunotherapy (relative risk (RR): 3.3 and RR 3.57). MN-BNHL patients with PPM1Dms exhibited improved survival compared to those without (p = 0.0376), but this benefit was negated by the presence of TP53 mutations (p = 0.0049). Conclusions: PPM1Dms are a prominent genetic feature in MN-BNHL, suggesting a distinct role in its development compared to MN-SC. Further investigation is needed to elucidate the precise contribution of PPM1D and its interaction with other mutations in BNHL-related myeloid neoplasm development and prognosis. Full article

Therapy-related myeloid neoplasms (t-MN) arise after a documented history of chemo/radiotherapy as treatment for an unrelated condition and account for 10–20% of myelodysplastic syndromes and acute myeloid leukemia. T-MN are characterized by a specific genetic signature, aggressive features and dismal prognosis. The nomenclature and the subsets of these conditions have changed frequently over time, and despite the fact that, in the last classification, they lost their autonomous entity status and became disease qualifiers, the recognition of this feature remains of major importance. Furthermore, in recent years, extensive studies focusing on clonal hematopoiesis and germline variants shed light on the mechanisms of positive pressure underpinning the rise of driver gene mutations in t-MN. In this manuscript, we aim to review the evolution of defining criteria and characteristics of t-MN from a clinical and biological perspective, the advances in mechanistic aspects of malignant progression and the challenges in prevention and management. Full article

There is a great deal of controversy in the hematologic community regarding the classification of secondary myelodysplastic neoplasms (MDSs). Current classifications are based on the presence of genetic predisposition and MDS post-cytotoxic therapy (MDS-pCT) etiologies. However, since these risk factors are not exclusive for secondary MDSs and there are multiple overlapping scenarios, a comprehensive and definitive classification is yet to come. In addition, a sporadic MDS might arise after a primary tumor fulfills the diagnostic criteria of MDS-pCT without a causative cytotoxicity. In this review, we describe the triggering pieces of a secondary MDS jigsaw: previous cytotoxic therapy, germline predisposition and clonal hematopoiesis. Epidemiological and translational efforts are needed to put these pieces together and ascertain the real weight of each of these pieces in each MDS patient. Future classifications must contribute to understanding the role of secondary MDS jigsaw pieces in different concomitant or independent clinical scenarios associated with the primary tumor. Full article