Acute B-Lymphoblastic Leukemia With Surface Immunoglobulin Light Chain Restriction: Case Report

Abstract

B-lymphoblastic leukemia (B-ALL) is a neoplasm of B lymphoblasts that are typically negative for surface immunoglobulin light chain with flow cytometry immunophenotype analysis. Few cases have been previously reported of B-ALL with surface immunoglobulin light chain restriction. Previous studies suggest that surface immunoglobulin light chain restriction in precursor B lymphoblasts is not confined to any particular stage of B-lymphoblast differentiation. This study reports a 26-year-old male having B-ALL with surface immunoglobulin light chain restriction. Immunophenotypic patterns were investigated by multiparametric flow cytometry. BCR-ABL1 transcripts were investigated using quantitative PCR, and cytogenetic and FISH analyses were performed to identify chromosomal alterations. At the time of the primary diagnosis, the leukemic cells in this patient had typical morphologic features of B-ALL; expressed CD10, CD19, CD15, CD38, HLA-DR, and CD34; and displayed surface immunoglobulin light chain restriction. The leukemic cells did not express CD20, CD2, CD3, CD4, CD8, CD5, CD7, CD56, TdT, and cMPO. Trisomy 11q and deletion of 21q were detected in this case, which are cytogenetic abnormalities often reported in B-ALL. These results evidence that a precursor B leukemia cannot be ruled out solely by the presence of surface immunoglobulin light chain restriction on leukemic cells by using flow cytometry immunophenotype analysis. The significance of this finding in the clinical course of B-ALL requires further investigation.