Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
Mod Pathol. 2010 Feb;23(2):235-43. doi: 10.1038/modpathol.2009.164. Epub 2009 Nov 20.
Primary central nervous system lymphomas are rare neoplasms characterized by a dismal prognosis relative to other extranodal lymphomas. Approximately 98% of primary central nervous system lymphomas are of B-cell origin, and most belong to the diffuse large B-cell type. Recently, diffuse large B-cell lymphomas have been subcategorized into germinal center and nongerminal center types based on gene expression profiles and immunohistochemical expression of CD10, Bcl-6, and MUM1. Studies have shown that the overall survival rate of the germinal center group is better than that of the nongerminal center lymphomas. In this study, 31 cases of primary central nervous system lymphomas of the diffuse large B-cell type were retrieved, reviewed, and immunostained for CD10, Bcl-6, MUM1, and Ki-67. Subclassification was carried out as described earlier, where CD10 and/or Bcl-6 positivity and negativity for MUM1 were considered characteristic of germinal center subtype and the opposite expression of nongerminal center subtype. Furthermore, the proliferative activity was semiquantitatively assessed using percent positive cells staining with Ki-67. Of the 31 cases examined, 26 (84%) were found to belong to the nongerminal center type. The Ki-67 index in these 26 cases ranged from 30 to 90% (mean, 69%). Five cases were categorized as the germinal center subtype. They had an Ki-67 index between 70 and 90% (mean, 78%). Interestingly, none of our patients were known to be HIV positive. One patient had a 10-year history of orthotopic liver transplant. We also performed fluorescence in situ hybridization analysis on formalin-fixed material and found that 38% of the cases where tissue was available had abnormalities of MYC/IGH and/or IGH/BCL2. We conclude that most primary central nervous system diffuse large B-cell lymphomas are of the nongerminal center origin. Regardless of the germinal center status, all cases showed a high proliferative rate. A statistically significant difference in the overall survival between the two groups was not seen.
原发性中枢神经系统淋巴瘤是一种罕见的肿瘤，与其他结外淋巴瘤相比，预后较差。约 98%的原发性中枢神经系统淋巴瘤为 B 细胞来源，大多数属于弥漫性大 B 细胞型。最近，根据基因表达谱和 CD10、Bcl-6 和 MUM1 的免疫组化表达，弥漫性大 B 细胞淋巴瘤已被细分为生发中心型和非生发中心型。研究表明，生发中心型的总生存率优于非生发中心型淋巴瘤。在本研究中，我们检索、复习并免疫组化染色了 31 例原发性中枢神经系统弥漫性大 B 细胞淋巴瘤病例，检测 CD10、Bcl-6、MUM1 和 Ki-67。如前所述进行分类，CD10 和/或 Bcl-6 阳性而 MUM1 阴性被认为是生发中心型的特征，而相反的表达则为非生发中心型。此外，用 Ki-67 阳性细胞百分比对增殖活性进行半定量评估。在检查的 31 例病例中，26 例（84%）被归类为非生发中心型。这 26 例病例的 Ki-67 指数范围为 30%至 90%（平均值，69%）。5 例归类为生发中心型。它们的 Ki-67 指数在 70%至 90%（平均值，78%）之间。有趣的是，我们的患者中没有已知的 HIV 阳性患者。一名患者有 10 年的原位肝移植病史。我们还对福尔马林固定的组织进行了荧光原位杂交分析，发现有组织的病例中 38%存在 MYC/IGH 和/或 IGH/BCL2 的异常。我们得出结论，大多数原发性中枢神经系统弥漫性大 B 细胞淋巴瘤来源于非生发中心。无论生发中心状态如何，所有病例均显示出高增殖率。两组之间的总生存率没有统计学上的显著差异。
