摘要： 研究背景 中枢神经系统原发性间变性大细胞淋巴瘤可发生于各年龄阶段，通常与免疫缺陷无关，临床及影像学检查易误诊为脑膜炎症性病变，尤其是结核性脑膜炎。而在病理诊断上，形态与中枢神经系统以外的间变性大细胞淋巴瘤相似，间变性淋巴瘤激酶1 可呈阳性或阴性。由于易误诊为脑膜炎而于组织活检前应用糖皮质激素治疗，造成组织学观察呈现大片坏死，以及大量组织细胞增生和吞噬现象，故在取材不够全面时易误诊为脑梗死或恶性组织细胞增生性疾病等。本文结合1 例12岁中枢神经系统原发性间变性大细胞淋巴瘤患儿的临床资料，通过相关文献回顾，总结该病发病特点和临床表现，以提高临床及病理医师对该病的认识。方法与结果 12岁男性患儿，临床表现为发热、头痛，伴右侧肢体麻木、无力。MRI 检查右侧顶叶局部脑回肿胀及软脑膜异常强化，并累及右侧颞叶；左侧顶叶软脑膜异常强化。右侧颞顶叶病变组织活检肿瘤细胞体积较大且形态不规则，胞质丰富、嗜伊红，可见马蹄形和肾形核。免疫组织化学检测肿瘤细胞CD3 、CD45RO 、CD30、间变性淋巴瘤激酶1 和上皮膜抗原表达阳性，CD20和CD79a 表达阴性。结论 间变性大细胞淋巴瘤是中枢神经系统的罕见病理亚型，临床及影像学极易误诊为脑膜炎症性病变。因此，对临床考虑为脑膜炎，但治疗效果差、病情反复的患者，应尽早进行脑组织活检或反复脑脊液细胞学检查，尤其是脑组织活检为明确诊断之重要手段。

关键词: 淋巴瘤, 大细胞, 间变性, 中枢神经系统, 结核, 脑膜, 免疫组织化学

Abstract: Background Primary anaplastic large T cell lymphoma (ALCL) of central nervous system (CNS) can occur in people of all ages, and is usually unrelated with immunodeficiency. It is often misdiagnosed as meningitis, especially tuberculous meningitis, on clinical practice and imaging examination. In pathological diagnosis, the morphological changes of primary ALCL of CNS are similar to the systemic ALCL and the anaplastic lymphoma kinase-1 (ALK-1) can be positive or negative. Being misdiagnosed as meningitis, hormone therapy with glucocorticoid before biopsy is always used, and massive necrosis and a lot of histocyte proliferation and phagocytosis can be found under histological findings. Therefore, when the material is not enough, primary ALCL of CNS is often misdiagnosed as cerebral infarction or malignant histocytosis and so on. This paper reports a case of primary ALCL of CNS and makes a review of relevant literature, so as to summarize the clinical manifestations and elevate the recognition of clinicians and pathologists on this disease. Methods and Results A 12-year-old boy was admitted because of fever, worsening headache, numbness and weakness of right limbs. MRI showed local gyri swelling and abnormal enhancement of pia mater in the right parietal lobe, expanding to the right temporal lobe, and pia mater enhancement in the left parietal lobe. The right temporo-parietal lobe lesion biopsy revealed irregularly shaped tumor cells of large size, rich and eosinophilic cytoplasm and horseshoe-shaped or kidney-shaped nuclei. Immunohistochemical examination showed tumor cells positive for CD3, CD45RO, CD30, ALK-1 and epithelial membrane antigen (EMA), and negative for CD20 and CD79a. Conclusion Primary ALCL of CNS is an extremely rare tumor which is usually misdiagnosed as meningitis according to clinical and imaging examinations. Therefore, for those patients who are considered as meningitis but with poor treatment effect and replase of illness, brain tissue biopsy, which is an important means for diagnosis, or cerebrospinal fluid cytologic examination, should be carried out as soon as possible.

Key words: Lymphoma, large-cell, anaplastic, Central nervous system, Tuberculosis, meningeal, Immunohistochemistry