Association Between B-Cell Marker Expression and <i>RUNX1</i> Lesions in Acute Myeloid Leukemia, Beyond <i>RUNX1</i>::<i>RUNX1T1</i> Fusion: Diagnostic Pitfalls with Mixed-Phenotype Acute Leukemia-B/Myeloid.

ABSTRACT: 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 A

SUBMITTER: George GV 

PROVIDER: S-EPMC12026294 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature