Interphase FISH for BCR‐ABL1 BCR‐ABL1 rearrangement on neutrophils: A decisive tool to discriminate a lymphoid blast crisis of chronic myeloid leukemia from a de novo BCR‐ABL1 BCR‐ABL1 positive acute lymphoblastic leukemia

摘要

Abstract Discrimination between lymphoid blast crisis of chronic myeloid leukemia (CML) and de novo BCR‐ABL1 positive acute lymphoblastic leukemia (ALL) represents a diagnostic challenge because this distinction has a major incidence on the management of patients. Here, we report an uncommon pediatric case of ALL with cryptic ins(22;9)(q11;q34q34) and p190‐type BCR‐ABL1 transcript. We performed interphase fluorescence in situ hybridization (FISH) for BCR‐ABL1 rearrangement on blood neutrophils, which was positive consistent with the diagnosis of lymphoid blast crisis of CML. This case illustrates the major interest of interphase FISH for BCR‐ABL1 rearrangement on blood neutrophils as a decisive method to discriminate a lymphoid blast crisis of CML from a de novo BCR‐ABL1 positive ALL.