背景：上皮样间皮瘤（EM）是恶性胸膜间皮瘤中最常见的亚型。其与反应性间皮增生（RMH）的组织病理学鉴别可能具有挑战性。因此，免疫组化面板对于更好的鉴别是必要的。BAP1是一种新鉴定的诊断标志物，其损失特异性针对恶性间皮瘤。EZH2过度表达在不同的癌症中有报道，但其与恶性间皮瘤中BAP1的关系尚未完全了解。据说，Survivin表达在EM中显著高于非肿瘤性胸膜组织，但其作为免疫组化标记的诊断效用尚未在这个领域得到彻底的研究。据我们所知，以前没有进行研究来评估这三个核标记物（BAP1、EZH2和Survivin）结合使用在鉴别胸膜EM和RMH中的诊断准确性。 方法：这项回顾性研究包括两组：81例胸膜EM和67例RMH，它们是从阿因沙姆斯大学医院病理科和阿因沙姆斯大学专科医院的档案中检索出来的，时间为2016年1月至2019年12月。使用BAP1、EZH2和Survivin抗体进行免疫组化研究。 结果：在所研究的标记物方面，研究组之间存在高度显着的关系（对于每个标记物，P = 0.001）。所有免疫组化标记物的特异性均为100％。此次研究中使用的任何免疫组化标记的灵敏度都比单独使用这些标记物的灵敏度要高。所有三个标记物的组合显示出最高的诊断准确性（95.9％）和最高的灵敏度（92.6％）。然而，Survivin和EZH2的组合产生了相同的诊断准确性和灵敏度。 结论：将EZH2、Survivin和BAP1添加到鉴别胸膜EM和RMH的诊断IHC面板中可以提高诊断灵敏度。此外，Survivin在这种情况下是一个潜在的有前途的标记物，特别是与EZH2结合时。版权所有© 2021 Hakim和Abou Gabal。

Background: Epithelioid mesothelioma (EM) is the commonest subtype of malignant pleural mesothelioma. Its histopathological discrimination from reactive mesothelial hyperplasia (RMH) could be challenging. Thus, an immunohistochemical panel is mandatory for better discrimination. BAP1 is a newly identified diagnostic marker whose loss is specific to malignant mesothelioma. EZH2 overexpression is reported in different cancers, but its relation to BAP1 in malignant mesothelioma has not been fully understood. Survivin expression is said to be significantly higher in EM than in non-neoplastic pleural tissue, but its diagnostic utility as an immunohistochemical marker has not been thoroughly investigated in this field. To the best of our knowledge, no previous studies have been conducted to assess the diagnostic accuracy of the combined use of these three nuclear markers (BAP1, EZH2 and Survivin) in discriminating pleural EM from RMH. Methods: This retrospective study includes two groups: 81 cases of pleural EM and 67 cases of RMH, retrieved from the archives of Pathology Department of Ain Shams University Hospitals and Ain-Shams University Specialized Hospital during the period from January 2016 to December 2019. An immunohistochemical study was performed using BAP1, EZH2 and Survivin antibodies. Results: There were highly statistically significant relations between study groups as regards the studied markers (p = 0.001 for each). The specificity was 100% for all combinations of immunohistochemical markers. Sensitivity of any combination of the immunohistochemical markers used in this study was found to be higher than the sensitivity of any of these markers used individually. The combination of all three markers showed the highest diagnostic accuracy (95.9%) and the highest sensitivity (92.6%). However, the combination of Survivin and EZH2 yielded the same diagnostic accuracy and sensitivity. Conclusion: Adding EZH2, Survivin and BAP1 to the diagnostic IHC panel for differentiating pleural EM and RMH could enhance diagnostic sensitivity. Moreover, Survivin is a potentially promising marker in this context, especially when combined with EZH2.Copyright © 2021 Hakim and Abou Gabal.