Marginal zone B-cell lymphomas (MZBCLs) are non-Hodgkin lymphomas arising from postgerminal center marginal zone B cells. MZBCLs are subclassified into extranodal, nodal, and splenic MZBCLs. Primary nondural central nervous system (CNS) MZBCLs of the mucosa-associated lymphoid tissue (MALT) type are among the extranodal examples. Their clinicopathological features are not well characterized. Therefore, the clinicopathological features of 8 primary nondural CNS MZBCLs of the MALT type were assessed to establish their pathological diagnostic criteria. Histologically, all cases of primary nondural CNS MZBCLs of the MALT type showed perivascular expansive monotonous proliferation of small atypical B lymphoid cells with plasma cell differentiation, low Ki-67 labeling index, and minimal invasion from the perivascular space. In addition, no vascular changes such as glomeruloid changes, obliterative fibrointimal proliferation, and intramural lymphocytic infiltration were seen. These key histological characteristics should be considered when diagnosing cases that are suspected to be primary nondural CNS MZBCLs of the MALT type. Additionally, regarding PCR for the detection of immunoglobulin heavy variable gene and T-cell receptor γ gene rearrangements, the former is detected, but the latter is not detected in all cases. Therefore, PCR detection including sequence analysis should be added when diagnosing difficult cases based on the key histological characteristics.

中文翻译：

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原发性非硬膜中枢神经系统边缘区B细胞淋巴瘤黏膜相关淋巴组织类型模仿中枢神经系统炎症性疾病

边缘区 B 细胞淋巴瘤 (MZBCL) 是起源于后生发中心边缘区 B 细胞的非霍奇金淋巴瘤。MZBCL 被细分为结外、淋巴结和脾脏 MZBCL。黏膜相关淋巴组织 (MALT) 类型的原发性非硬膜中枢神经系统 (CNS) MZBCL 属于结外示例。他们的临床病理学特征没有很好的表征。因此，评估了 8 例 MALT 型原发性非硬脑膜中枢神经系统 MZBCL 的临床病理特征，以确定其病理诊断标准。组织学上，所有 MALT 型原发性非硬脑膜中枢神经系统 MZBCL 病例均表现为血管周围小非典型 B 淋巴细胞扩张单调增殖，伴有浆细胞分化，Ki-67 标记指数低，血管周围间隙浸润极小。此外，未见肾小球样改变、闭塞性纤维内膜增生、壁内淋巴细胞浸润等血管变化。在诊断疑似 MALT 型原发性非硬膜 CNS MZBCL 的病例时，应考虑这些关键的组织学特征。另外，关于检测免疫球蛋白重可变基因和T细胞受体γ基因重排的PCR，检测到的是前者，但并非在所有情况下都检测到后者。因此，在根据关键组织学特征诊断疑难病例时，应增加包括序列分析在内的PCR检测。在诊断疑似 MALT 型原发性非硬膜 CNS MZBCL 的病例时，应考虑这些关键的组织学特征。另外，关于检测免疫球蛋白重可变基因和T细胞受体γ基因重排的PCR，检测到的是前者，但并非在所有情况下都检测到后者。因此，在根据关键组织学特征诊断疑难病例时，应增加包括序列分析在内的PCR检测。在诊断疑似 MALT 型原发性非硬膜 CNS MZBCL 的病例时，应考虑这些关键的组织学特征。另外，关于检测免疫球蛋白重可变基因和T细胞受体γ基因重排的PCR，检测到的是前者，但并非在所有情况下都检测到后者。因此，在根据关键组织学特征诊断疑难病例时，应增加包括序列分析在内的PCR检测。