Pediatric T‐Lymphoblastic Leukemia With Aberrant B‐Cell Marker Expression: A Potential Role for Targeted Therapy

Background Expression of B‐cell antigens is rare in T‐lymphoblastic leukemia/lymphoma (T‐LBLL), and the significance is uncertain. Objective and Methods We present a pediatric case of acute leukemia characterized by the expression of T‐cell markers and CD19, as determined by multicolor flow cytometry (MFC). Next‐generation sequencing (NGS) revealed a SET::NUP214 gene fusion. The patient was treated with conventional intensive acute lymphoblastic leukemia (ALL) therapy. The end‐of‐induction evaluations showed significant residual disease. Results While the patient failed high‐risk T‐LBLL induction therapy, blinatumomab followed by decitabine and venetoclax induced a morphologic remission. He then underwent a bone marrow stem cell transplant (BMSCT) and achieved a complete molecular remission. Conclusions This case illustrated the importance of integrating MFC analysis with NGS data to provide individualized patient treatment. Trial Registration The authors have confirmed clinical trial registration is not needed for this submission.