Johnson, Laura J.

BackgroundB‐lymphoblastic leukemias (B‐LBL) with combined IGH/BCL2 and MYC rearrangement are rare and their clinical, cytogenetic and immunophenotypic features are not well characterized. Here, we describe a case of a 61‐year‐old woman with B‐LBL associated with these cytogenetic alterations and present a review of the literature of this disease.MethodsFour‐color flow cytometry (FC) was performed on a BD FACSCanto II flow cytometer. Data were analyzed with BD FACSDiva software. Cytogenetic, fluorescence in situ hybridization (FISH), and molecular studies were performed by conventional methods. A review of the literature was performed by a PubMed‐assisted search.ResultsIncluding our case, eight B‐LBLs associated with a documented “double‐hit” karyotype (IGH/BCL2 and 8q24/MYC rearrangement) were identified in the literature (male/female 2/6, age 15‐65). Three occurred de‐novo, and five had a history of a CD10+ B‐cell lymphoma. The typical immunophenotype was CD10, CD19, TdT positive, and negative for CD34 and surface immunoglobulin (Ig), established either by FC or immunohistochemistry. Seven cases were CD20‐, and one case was CD20+. Translocation partners of MYC varied, and included IGH, lambda light chain, and an unknown gene on chromosome 9. Prognosis was poor with median survival of five months.ConclusionsPatients with B‐LBL associated with a combined IGH/BCL2 and MYC rearrangement often have a history of a mature B‐cell lymphoma. The immunophenotype of these cases is different from that of mature “double‐hit” lymphomas; FC is essential to differentiate the B‐LBL cases from the leukemic phase of mature B‐cell lymphomas. © 2015 International Clinical Cytometry Society