Yin Liqun, Xu Jie, Li Min, Reddy Vishnu, Zhou Quan, Liu Huanxin, Chu Peiguo, Zhang Qianyun, Huang Qin, Gao Zifen, Liang Xiayuan, Wang Huan-You, Pan Zenggang
Department of Pathology, University of Colorado Denver, Aurora, CO, USA.
Department of Hematopathology, MD Anderson Cancer Center, Houston, TX, USA.
Histopathology. 2016 Nov;69(5):775-783. doi: 10.1111/his.13017. Epub 2016 Aug 5.
Rare cases of B cell lymphomas do not express conventional B cell markers (CD20, CD79a and PAX5), and these types of lymphomas include anaplastic lymphoma kinase (ALK)-positive large B cell lymphoma, plasmablastic lymphoma, primary effusion lymphoma and the solid variant of primary effusion lymphoma, extracavitary human herpesvirus 8 (HHV8)-positive large B cell lymphoma. Establishing accurate diagnoses of these B cell lymphomas can be challenging, and often requires a large panel of immunohistochemical stains, molecular assays and cytogenetic studies. B cell-specific transcription factors, Oct2 and Bob1, have been shown to be expressed consistently in most, if not all, B cell lymphomas, and therefore we investigated the utility of Oct2 and Bob1 immunohistochemistry in lineage determination of the aforementioned B cell lymphomas.
We selected 34 cases of previously diagnosed B cell lymphomas with no or weak expression of CD20, CD79a and PAX5. Oct2 and Bob1 were positive in 74% (25 of 34) and 85% (29 of 34) of the cases, respectively. When we combined the results of these two immunostains, 94% (32 of 34) cases expressed at least one of these two markers. We also included 51 control cases of non-B cell neoplasms, and none of them expressed either Oct2 or Bob1.
Oct2 and Bob1 are very reliable in determining B cell lineage in the absence of expression of other pan-B cell markers, and it should provide great diagnostic benefit to include them both in a panel of immunohistochemistry to assess undifferentiated malignant neoplasms.
罕见的B细胞淋巴瘤不表达传统的B细胞标志物（CD20、CD79a和PAX5），这类淋巴瘤包括间变性淋巴瘤激酶（ALK）阳性大B细胞淋巴瘤、浆母细胞性淋巴瘤、原发性渗出性淋巴瘤以及原发性渗出性淋巴瘤的实体变体、腔外人类疱疹病毒8（HHV8）阳性大B细胞淋巴瘤。对这些B细胞淋巴瘤进行准确诊断具有挑战性，通常需要大量免疫组织化学染色、分子检测和细胞遗传学研究。B细胞特异性转录因子Oct2和Bob1已被证明在大多数（如果不是全部）B细胞淋巴瘤中持续表达，因此我们研究了Oct2和Bob1免疫组织化学在上述B细胞淋巴瘤谱系确定中的效用。
我们选择了34例先前诊断的CD20、CD79a和PAX5无表达或弱表达的B细胞淋巴瘤病例。Oct2和Bob1分别在74%（34例中的25例）和85%（34例中的29例）的病例中呈阳性。当我们将这两种免疫染色结果结合起来时，94%（34例中的32例）的病例表达了这两种标志物中的至少一种。我们还纳入了51例非B细胞肿瘤对照病例，它们均未表达Oct2或Bob1。
在缺乏其他泛B细胞标志物表达的情况下，Oct2和Bob1在确定B细胞谱系方面非常可靠，将它们纳入免疫组织化学检测组以评估未分化恶性肿瘤应具有很大的诊断价值。
