A new case of trisomy 5 with complex karyotype abnormalities in B-cell prolymphocytic leukemia: a case study

Abstract Background The B-cell prolymphocytic leukemia (B-PLL) diagnosis is challenging due to the superposition with mature B-cell leukemia and/or lymphoma. Objective An insight case study of trisomy 5 with complex karyotype abnormalities in B-cell prolymphocytic leukemia. Subject and methods A 72-year-old man was referred to the Hematology Department, Qilu Hospital, Shandong University, because of persistent fever (10 days) and lymphocytosis. A detailed diagnostic methods including complete blood count, bone marrow aspiration, flow cytometry, conventional karyotype analysis, fluorescence in situ hybridization (FISH), quantitative real-time polymerase chain reaction (qRT-PCR), next-generation sequencing technology (NGS) used to detect 41 kinds of mutant genes related to hematological malignancies were conducted and reasonable therapeutic regimens including emergent leukapheresis accompanied by basification of urine and hydrotherapy, followed by a regimen of cyclophosphamide and dexamethasone. Results Subject white blood cell count was 143.43 × 109/L, and 56% prolymphocytes. He did not show lymphadenopathy but splenomegaly. Immunophenotyping of prolymphocytes was CD5(+low), CD10(−), CD11c(−), CD19(+), CD20(+), cCD22(+), CD23(−), cCD79a(+), CD79b(+), FMC7(±), CD43(−), CD3(−), CD56(−), CD103(−), HLA-DR(+), and Lambda(+). R-banding and FISH revealed that leukemia cells carried extra chromosome 5. Considering the rare occurrence of trisomy 5 found in prolymphocytic leukemia, especially in Asians, with rapid disease progression. We know that median survival of B-PLL is three years after diagnosis, while survival time of this patient was only 1 month. Conclusion This study could provide the firsthand materials for precision, medicine and mechanism research in cytogenetics and molecular biology. It inferred that trisomy 5 might be a poor prognosis indicator, providing directions for clinical practice in the foreseeable future.