脑室内外神经细胞瘤的影像特征及鉴别诊断

Neuroradiological Features of Intraventricular Central Neurocytoma and Extraventricular Neurocytoma

目的:探讨脑室内外神经细胞瘤的CT和MRI特征以及病理表现,以提高诊断正确率。方法:回顾性分析15例经病理证实的中央神经细胞瘤(CN)以及1例脑室外神经细胞瘤(EVN)临床资料、CT及MRI特征,对肿瘤的发病部位、形状、边界、囊变、钙化、有无出血以及强化特征进行分析。结果:15例中央神经细胞瘤均位于侧脑室前部靠近透明隔。肿瘤实质在CT上呈等密度或稍高密度伴多发囊变,6例伴钙化;MRI所有肿瘤均见囊变,2例肿瘤内可见流空血管影以及出血;增强后肿瘤呈轻度至明显强化。1例脑室外神经细胞瘤位于右侧额颞叶,边界不清,可见钙化、出血以及囊变,实质部分明显强化。结论:中央神经细胞瘤影像表现具有一定特征性,当肿瘤位于脑室内近透明隔,并钙化以及囊变、结合患者年龄多能做出正确诊断。当年轻患者肿瘤较大且位于脑实质合并钙化、囊变和(或)出血,应当考虑脑室外神经细胞瘤的可能,但其影像表现多样,确诊需要依靠病理检查。

Purpose：To study the CT and MRI characteristics of intra-and exraventricular neurocytomas.Methods：The imaging findings and clinical history of 15 central neurocytomas and 1 exraventricular neurocytoma were analyzed retrospectively.The imaging data were analyzed with regard to lesion location,size,margin,mass effect,signal intensity,enhancement characteristics,presence of calcifications and cystic changes.Results：All 15 intraventricular central neurocytomas tumors were located in the lateral ventricles and closed to the septum pellucidum.The tumors presented hypointensity or isointensity on T1WI and hyperintensity on T2WI with cystic areas and haemorrhages and mild to marked inhomogeneous enhancement.One exraventricular neurocytoma demonstrated the feature of the progression from no calcification to multiple stripped calcifications within the ill defined mass during 8-year following-up on CT and cystic degeneration and hemorrhage in the mass with moderate enhancement on MRI.Conclusion： Central neurocytoma is charicteristic on CT and MRI,and should be considered when a mass originates from the septum pellucidum and lateral ventricle in a young patient.Extraventricular neurocytoma should be considered for differential diagnosis when a large cerebral parenchymal mass with cystic necrosis,calcification,and/or hemorrhage foci,and extensive enhancement is encountered in younger patients.