Lin Pei, Jetly Rechna, Lennon Patrick A, Abruzzo Lynne V, Prajapati Sapana, Medeiros L Jeffrey
Department of Hematopathology, The University of Texas, M D Anderson Cancer Center, Houston, TX 77030, USA.
Hum Pathol. 2008 Nov;39(11):1664-72. doi: 10.1016/j.humpath.2008.04.007. Epub 2008 Jul 24.
Follicular lymphomas characteristically carry t(14;18)(q32;q21) which results in IGH-BCL-2 fusion. Variant translocations that juxtapose the BCL-2 gene with the immunoglobulin kappa (2p11) and lambda (22q11) light chain genes are rare. We report 4 cases of B-cell lymphoma/leukemia associated with t(18;22)(q21;q11). The t(18;22)(q21;q11) was the sole aberration identified by conventional cytogenetics in 2 cases. Three cases were classified as chronic lymphocytic leukemia, and one as follicular lymphoma based on morphology and immunophenotype. Fluorescence in situ hybridization analysis was performed on all 4 cases using a BCL-2 breakapart probe. The BCL-2 gene was rearranged in all cases. Immunoglobulin lambda light chain gene rearrangement was shown in 3 cases using bacterial artificial chromosome probes spanning the variable and constant clusters of the IGlambda gene. Each case was negative for MALT-1 rearrangement using a MALT-1 breakapart probe. These cases illustrate that t(18;22)(q21;q11) is more commonly observed in chronic lymphocytic leukemia and may represent either an initial or secondary genetic event.
滤泡性淋巴瘤的特征性表现是携带t(14;18)(q32;q21)，这会导致IGH-BCL-2融合。将BCL-2基因与免疫球蛋白κ(2p11)和λ(22q11)轻链基因并列的变异易位很少见。我们报告了4例与t(18;22)(q21;q11)相关的B细胞淋巴瘤/白血病。在2例病例中，t(18;22)(q21;q11)是常规细胞遗传学鉴定出的唯一异常。根据形态学和免疫表型，3例被分类为慢性淋巴细胞白血病，1例为滤泡性淋巴瘤。使用BCL-2分离探针对所有4例病例进行了荧光原位杂交分析。所有病例中BCL-2基因均发生重排。使用跨越IGλ基因可变和恒定簇的细菌人工染色体探针，在3例病例中显示了免疫球蛋白λ轻链基因重排。使用MALT-1分离探针，每例病例的MALT-1重排均为阴性。这些病例表明，t(18;22)(q21;q11)在慢性淋巴细胞白血病中更常见，可能代表原发性或继发性遗传事件。
