原发中枢神经系统淋巴瘤样肉芽肿病的MRI表现

MRI manifestations of primary central nervous system lymphomatoid granulomatosis

目的提高对原发中枢神经系统淋巴瘤样肉芽肿病(LyG)的MRI表现的认识。方法总结首都医科大学宣武医院经手术或活检病理证实的3例原发中枢神经系统LyG,分析其MRI表现与组织病理学所见,并复习相关文献。结果 3例患者的MRI均表现为脑内多发病变,受累部位分别为左侧侧脑室颞角和枕角旁、左侧额颞叶和侧脑室旁、双侧额叶,病变在T1WI为低信号、T2WI为高信号,DWI无明显弥散受限,病变周围伴有明显水肿,增强后呈多发结节状、环状或片状明显强化。组织病理学上表现为以血管为中心的T细胞为主的淋巴细胞浸润,破坏血管壁,伴吞噬细胞浸润及反应性星形细胞增生,部分B细胞有异型性。结论原发中枢神经系统LyG是一种罕见的淋巴细胞增生性疾病,MRI有很高的敏感性和一定的特异性,临床工作中应将LyG纳入脑内多发强化病变的鉴别诊断范畴内。

Objective To better realize the MRI features of primary central nervous system lymphomatoid granulomatosis （LyG）. Methods Three cases of primary central nervous system LyG, which were pathologically diagnosed after operation or biopsy, were reported, and their MRI and pathological manifestations were analyzed with pertinent literature review. Results MRI of all the 3 patients showed multi-foci lesions, which affected paraventricular regions next to the left temporal and occipital horns, left frontal and temporal lobes and left paraventricular regions, and bi-frontal lobes, respectively. All these lesions manifested as hypointensity on T1WI, hyperintensity on T2WI, without obvious diffusion restriction on DWI, and always accompanied by a large parafoci edema. After contrast, they showed multiple nodular, ring or patchy enhancement. Histopathological findings were lesions characterized by angiocentric and angiodestructive T cell predominant lymphoproliferation and infiltration, along with macrophage infiltration and astrocyte activation, partly showed atypical B cells. Conclusion Primary central nervous system LyG is a rare lymphoproliferative disease, which can be sensitively detected by MRI with certain specificity, and it should be considered in the differential diagnosis of multiple intracranial lesions with enhancement.