Objective: To evaluate the expression of LEF1 protein in lymphoblastic lymphoma/acute lymphoblastic leukemia (LBL/ALL) and small B-cell lymphomas, and its value in pathologic diagnosis and differential diagnosis of LBL/ALL. Methods: 53 cases of LBL/ALL were collected at shanghai Tongji Hospital from January 2012 to December 2019. The protein expression of LEF1 and TdT was detected by immunohistochemistry in 53 paraffin-embedded tissue samples of LBL/ALL. The specificity and sensitivity of LEF1 and TdT in the diagnosis of LBL/ALL were compared. The expression of LEF1 protein in 77 cases of small B-cell lymphomas including chronic lymphocytic leukemia/small lymphoid lymphoma (CLL/SLL), follicular lymphoma, mantle cell lymphoma, marginal zone lymphoma and Waldenstrom's macroglobulinemia/lymphoplasmacytic lymphoma was studied. The correlation between LEF1 expression and overall survival (OS) and progression-free survival (PFS) was performed by univariate analysis. Results: The expression of LEF1 in LBL/ALL was 100% (53/53), the median value was 90%; the expression of TdT was 84.9% (T-LBL/ALL 78.1%, B-LBL/ALL 95.2%), the median value was 80%; the expression rate and median value of LEF1 and TdT were significantly different (P=0.008 and 0.001 respectively). The expression of LEF1 in CLL/SLL was 14/18, the median value was 45%; LEF1 was not expressed in follicular lymphoma (0/16), mantle cell lymphoma (0/16), marginal zone lymphoma (0/19), and Waldenstrom's macroglobulinemia/lymphoplasmacytic lymphoma (0/8). LEF1 expression was significantly different between B-LBL/ALL and small B-cell lymphomas. The median follow-up time of LBL/ALL cases in this group was 16 months. There was no statistical difference between LEF1 expression and the OS and PFS in LBL/ALL patients. Conclusions: Immunohistochemical staining of LEF1 has high sensitivity and good specificity in the diagnosis of LBL/ALL, and its combination with TdT can improve the diagnostic rate of LBL/ALL.
目的： 研究淋巴样增强结合因子1（LEF1）蛋白在淋巴母细胞淋巴瘤/急性淋巴细胞白血病（LBL/ALL）和小B细胞淋巴瘤中的表达，探讨其在LBL/ALL病理诊断及鉴别诊断中的价值。 方法： 收集2012年1月至2019年12月上海市同济医院就诊及会诊的53例LBL/ALL石蜡组织标本，采用免疫组织化学法检测LEF1、末端脱氧核苷酸转移酶（TdT）蛋白表达，比较LEF1和TdT诊断的特异度、灵敏度。检测小B细胞淋巴瘤包括慢性淋巴细胞白血病/小淋巴细胞淋巴瘤（CLL/SLL）、滤泡性淋巴瘤、套细胞淋巴瘤、边缘区B细胞淋巴瘤、华氏巨球蛋白血症/淋巴浆细胞淋巴瘤共77例LEF1蛋白表达，比较LBL/ALL与各亚型小B细胞淋巴瘤LEF1蛋白表达差异。单因素分析LEF1蛋白表达与LBL/ALL患者总生存与无进展生存的相关性。 结果： LBL/ALL中LEF1蛋白表达阳性率为100%（53/53），中位值90%；TdT阳性率为84.9%（45/53；T-LBL/ALL为78.1%，B-LBL/ALL为95.2%），中位值80%；LEF1和TdT阳性率及中位值差异均有统计学意义（P值分别为0.008，0.001）。CLL/SLL LEF1蛋白表达阳性比例为14/18，中位值45%；滤泡性淋巴瘤（0/16）、套细胞淋巴瘤（0/16）、边缘区B细胞淋巴瘤（0/19）、华氏巨球蛋白血症/淋巴浆细胞淋巴瘤（0/8）LEF1蛋白均为阴性。B-LBL/ALL与小B细胞淋巴瘤比较，LEF1阳性率有显著差异。本组LBL/ALL病例中位随访时间16个月，LEF1蛋白表达与LBL/ALL总生存和无进展生存差异无统计学意义。 结论： LEF1免疫组织化学检测诊断LBL/ALL有很高的灵敏度和较好的特异度，与TdT联用可提高LBL/ALL诊断率。.