脑室内多形性黄色星形细胞瘤的MRI表现及文献复习

MRI Findings of Intraventricular Pleomorphic Xanthoastrocytoma and Review of Literature

目的探讨脑室内多形性黄色星形细胞瘤(PXA)的MRI表现。方法搜集经病理证实的2例脑室内PXA患者,2例均行MR平扫及增强扫描;总结其临床、MRI表现及病理资料。结果男、女各1例,年龄分别为20岁和26岁,1例位于第三脑室、1例位于右侧脑室后角。2例均表现为头晕、头痛,1例伴有间断性眼部疼痛。大小分别为0.8 cm×0.8 cm×1.0 cm和5.7 cm×7.1 cm×8.2 cm。第三脑室病灶MRI表现为T1WI呈等稍低信号,T2WI和T2WI液体衰减反转恢复(FLAIR)呈高信号,内部见结节状低信号,扩散加权成像(DWI)呈等信号,增强后明显不均匀强化,周围见水肿带。右侧脑室后角病灶MRI表现为T1WI呈等信号,T2WI信号混杂,内见多发条状、条片状稍高信号及囊状高信号,T2WI FLAIR实性部分呈高信号,增强后分隔及实性部分轻中度强化,周围见轻度水肿带。病理学表现为肿瘤细胞弥漫分布,瘤细胞呈卵圆形或胖梭形,体积大,胞浆丰富,可见多形、怪异及多核瘤细胞,细胞异型性无或明显,免疫组织化学GFAP、S-100、P53均为阳性。结论脑室内PXA的MRI表现缺乏特征性,青年患者脑室内肿瘤,要考虑到该病的可能,最终确诊需要根据病理及免疫组织化学检查。

Objective To investigate the MRI findings of intraventricular pleomorphic xanthoastrocytoma(IPXA). Methods Two patients with IPXA confirmed by pathology were examined by plain and enhanced MR,and the clinical, MRI manifestations and pathological data were summarized. Results The age was 20~26 years old.There were 1 male and 1 female, 1 in the third ventricle and 1 in the posterior horn of the lateral ventricle.2 cases showed dizziness and headache, and 1 case was accompanied by intermittent eye pain.The volume is different, 0.8 cm×0.8 cm×1.0 cm-5.7 cm×7.1 cm×8.2 cm.MRI of the third ventricle showed hypointensity or slightly hypointensity of T1WI,hyperintensity of T2WI and T2FLAIR,hypointensity inside, iso-signal of DWI,obvious inhomogeneous enhancement and edema zone around it.MRI of the posterior horn of the right ventricle showed isointense T1WI,mixed T2WI signals, multiple striped, patchy and cystic hyperintensity, hyperintensity in the solid part of T2FLAIR,mild to moderate enhancement of the enhanced septum and solid part, and mild edema around it.Pathology showed that the tumor cells were diffusely distributed, the tumor cells were oval or fat fusiform, large in volume, rich in cytoplasm, pleomorphic, strange and multinucleated tumor cells could be seen.There was no or obvious heteromorphism of tumor cells.Immunohistochemical GFAP,S100,p53 were positive. Conclusion MRI findings of IPXA are lack of characteristics, young patients with intraventricular tumors, in order to consider the possibility of this disease, the final diagnosis needs to be based on pathological and immunohistochemical examination.