Immunophenotypic and cytogenetic findings of B-lymphoblastic leukemia/lymphoma associated with combined IGH/BCL2 and MYC rearrangement.

BACKGROUND: B-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.

METHODS: Four-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.

RESULTS: Including 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.

CONCLUSIONS: Patients 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.