建议使用断裂探针进行荧光原位杂交 (FISH) 来鉴定具有 MYC 和 BCL2 重排 (HGBCL-DH-BCL2) 的高级别 B 细胞淋巴瘤。临床实验室通常将不平衡的 MYC 分解模式（红色或绿色信号丢失）报告为模棱两可的结果。在 297 个 HGBCL-DH-BCL2 队列中，13% 的肿瘤具有不平衡的 MYC 分裂模式，伴有红色（LR：2%）或绿色（LG：11%）信号丢失。为了确定这些模式的重要性，通过对 130 个 HGBCL-DH-BCL2（包括 3 个 LR 肿瘤和 14 个 LG 肿瘤）进行测序来表征 MYC 重排。 71% 具有 LR 或 LG 模式的肿瘤存在 MYC 重排，其中大多数涉及免疫球蛋白位点或其他复发性 MYC 重排伙伴。这些重排的结构一致地保留了重排的 MYC 等位基因，MYC 基因预计位于包含几乎所有情况下仍然存在的信号的衍生染色体上。平衡组和不平衡组之间的 MYC 蛋白表达、MYC mRNA 表达和表达暗区特征的肿瘤比例没有显着差异。这些结果支持以下建议：在诊断 HGBCL-DH-BCL2 的背景下，将不平衡的 MYC 分离 FISH 模式报告为 MYC 重排阳性。版权所有 © 2024 美国血液学会。

Fluorescence in situ hybridization (FISH) using break-apart probes is recommended for identifying high-grade B-cell lymphoma with MYC and BCL2 rearrangements (HGBCL-DH-BCL2). Unbalanced MYC break-apart patterns, where the red or green signal is lost, are commonly reported as an equivocal result by clinical laboratories. In a cohort of 297 HGBCL-DH-BCL2, 13% of tumors had unbalanced MYC break-apart patterns with loss of red (LR: 2%) or green (LG: 11%) signal. To determine the significance of these patterns, MYC rearrangements were characterized by sequencing in 130 HGBCL-DH-BCL2, including 3 LR and 14 LG tumors. A MYC rearrangement was identified for 71% of tumors with LR or LG patterns, with the majority involving immunoglobulin loci or other recurrent MYC rearrangement partners. The architecture of these rearrangements consistently preserved the rearranged MYC allele, with the MYC gene predicted to be on the derivative chromosome containing the signal that is still present in nearly all cases. MYC protein expression, MYC mRNA expression, and the proportion of tumors expressing the dark zone signature was not significantly different between balanced and unbalanced groups. These results support a recommendation that unbalanced MYC break-apart FISH patterns be reported as positive for MYC rearrangement in the context of diagnosing HGBCL-DH-BCL2.Copyright © 2024 American Society of Hematology.