Abstract:

Objective  To explore the clinical and pathological characteristics, diagnosis and differential diagnosis of IgG4-related meningeal disease.  Methods and Results  A 49-year-old male patient suffered from headache for nearly 2 years and the symptom was aggravated progressively for over one month. MRI revealed space-occupying lesion in left parietal lobe, with irregular signal and clear borderline. Contrast-enhanced MRI showed homogeneous enhancement, and obvious meningeal thicking just like "dural tail sign". The patient underwent operation, and the lesion was totally removed. Histologically, it showed a large amount of hyperplastic collagen fibrous tissue with inflammatory cells, including a large number of plasmocytes, as well as scattered lymphocytes and a small number of eosinophilic granulocytes. Russell bodies which were homogenously positive for eosin could be seen in some plasmocytes. Focal necrosis, and proliferation of interstitial fibroblasts and small vessels were found. The lesion had no capsules and invaded surrounding tissues. Immunohistochemical staining showed the plasmocytes were diffusely positive for IgG and IgG4 (> 60%), and were positive for CD38 and CD138 on the membrane. Lymphocytes were positive for CD3, CD4 or CD20 on the membrane. The serum IgG4 level was 1.05 g/L. Final pathological diagnosis was IgG4-related meningeal disease in left parietal lobe. After operation, the patient received anti-infectious, anti-epileptic and nutrition support treatment, and the symptoms were markedly improved. The patient was discharged after 26 d, but was lost to follow-up.  Conclusions IgG4-related meningeal disease is a rare disease. Due to the atypical imaging features, it may be difficult to differentiate IgG4-related meningeal disease from other diseases with prominent inflammatory cells and stromal fibrosis. The elevated serum IgG4 level may provide diagnostic cues. However, a definite diagnosis depends on characteristic histological and immunohistochemical features.

Key words: Immunoglobulin G, Meninges, Pathology, Immunohistochemistry

摘要：

目的 探讨IgG4 相关性脑膜病变的临床病理学特征以及诊断与鉴别诊断要点。方法与结果 男性患者，49 岁，临床表现为头痛近2 年并进行性加重1月余，头部MRI 显示左侧顶叶占位性病变，增强扫描可见“脑膜尾征”，手术完整切除病灶。组织学形态，左侧顶叶硬脑膜和脑实质大量胶原纤维增生，其间散在灶状细胞浸润，多为较成熟的浆细胞，部分浆细胞内可见匀质红染的Russell 小体，其间散在淋巴细胞和少量嗜酸性粒细胞，局部可见小灶状坏死，间质纤维母细胞和小血管增生，未见包膜，病变累及周围脑组织。免疫组织化学染色，浆细胞胞质弥漫性表达IgG 和IgG4（> 60%）、胞膜表达CD38和CD138，淋巴细胞胞膜表达CD3、CD4 或CD20。血清IgG4 为1.05 g/L。最终病理诊断为（左侧顶叶）IgG4 相关性脑膜病变可能性大。术后予抗感染、抗癫、营养支持治疗，症状明显好转，出院后未按医嘱定期随访。结论 IgG4相关性脑膜病变临床少见，且缺乏典型临床表现和特征性影像学改变，术前诊断与鉴别诊断困难，血清IgG4 水平升高是其诊断的重要线索，明确诊断仍需依靠特征性的组织学形态和免疫组织化学表型。

关键词: 免疫球蛋白G, 脑膜, 病理学, 免疫组织化学