摘要：

目的 回顾1 例弥漫性大B 细胞淋巴瘤不同发病阶段的临床、影像学和病理学特点，并分析其可能的发生机制。 方法与结果 女性患者，29 岁，汉族。首次发病以视物模糊、视野缺损为主要临床表现；头部MRI显示右侧顶枕叶皮质下斑片状T₁WI稍低信号、T₂WI和FLAIR 成像高信号，无明显占位效应，增强扫描病灶呈点状强化；激素冲击治疗后病灶逐渐消失。再次发病以头痛、呕吐和左侧肢体瘫痪为主要临床表现；头部MRI显示右侧额顶叶大片状T1WI低信号、T₂WI和FLAIR 成像高信号，占位效应明显，增强扫描病灶呈实性强化。于手术显微镜下全切除肿瘤。组织学形态观察，肿瘤细胞体积较大，胞质较丰富，胞核大小形态不一，核分裂象易见，片状坏死，间质小血管增生。免疫组织化学染色，肿瘤细胞胞膜CD20、胞核配对盒基因5 和多发性骨髓瘤癌基因1 呈阳性，少数肿瘤细胞胞膜CD10 和D30、
胞核周期蛋白D1 呈阳性，CD3、间变性淋巴瘤激酶和胶质纤维酸性蛋白呈阴性，Ki-67 抗原标记指数为80%。EBER 原位杂交检测EB 病毒编码mRNA 呈阴性。肿瘤组织呈明显噬血管特性，围绕并侵犯血管壁，最终病理诊断为弥漫性大B 细胞淋巴瘤。 结论 原发性中枢神经系统淋巴瘤的影像学表现多样，呈实性占位性或浸润性病变，是肿瘤发病不同阶段的不同表现，与肿瘤嗜血管特性有关。

关键词: 淋巴瘤, 大B 细胞, 弥漫性, 免疫组织化学, 磁共振成像, 病理学

Abstract:

Objective   The clinical, imaging and pathological manifestations of one patient at different stages of primary central nervous system lymphoma (PCNSL) have been analyzed to disclose its pathogenesis.   Methods and Results   A 29-year-old female patient showed recurrent onsets. On the first onset, the main clinical manifestation was blurred vision and visual field defect. Cranial MRI showed a patchy lesion in the right parietal and occipital lobes without obvious occupying sign. T₁WI showed slight low-intensity sign, T₂WI and FLAIR showed high-intensity signs. Enhanced scanning showed heterogeneous punctate enhancement. The lesion disappeared gradually after glucocorticoid impact therapy. Headache, vomiting and left limb paralysis were the main clinical manifestations on the second onset, and MRI showed a lesion in the right frontal and parietal lobes with obvious occupying sign and solid enhancement, low-intensity on T₁WI, high-intensity on T₂WI and FLAIR. The tumor was totally removed under microscope. Histological findings showed large tumor cells, rich cytoplasm, nuclei with various sizes and shapes, conspicuous mitosis, patchy necrosis, and interstitial small vessel hyperplasia. Immunohistochemical staining showed that membrane of tumor cells was positive for CD20, and nuclei were positive for paired box gene 5 (PAX5) and multiple myeloma oncogene 1 (MUM1). In a few tumor cells, membrane was positive for CD10 and CD30, and nuclei were positive for cyclin D1. Besides, tumor cells were negative for CD3, anaplastic lymphoma kinase (ALK) and glial fibrillary acidic protein (GFAP). Ki?67 labeling index was about 80%. EBER in situ hybridization (ISH) assay showed that mRNA coded by Epstein?Barr (EB) virus was negative. The tumor showed angiotropic characteristics, and the walls of involved blood vessels were wrapped and destructed. The final diagnosis was confirmed as diffuse large B cell lymphoma.  Conclusions  PCNSL has various imaging features, revealing as diffuse infiltrating or solid occupying lesions, which emerge as the result of its angiotropic characteristics.

Key words: Lymphoma, large B-cell, diffuse, Immunohistochemistry, Magnetic resonance imaging, Pathology