非典型多形性黄色星形细胞瘤的MRI及病理表现

MRI and pathology features of atypical pleomorphic xanthoastrocytoma

目的:探讨分析实质型多形性黄色星形细胞瘤(PXA)的临床、病理及影像学表现特征。方法:回顾性分析经病理证实的23例PXA患者的临床、病理及影像学资料,重点观察、分析11例实质型PXA的病变部位、病灶大小、瘤周水肿、恶变发生率及MRI信号特征。结果:11例实质型PXA患者中,发病平均年龄为(31.0±9.7)岁,9例(81.8%)病程≤1年;病变累及颞叶8例(72%),岛叶3例(27%),囊变发生率为72.7%(8/11);实质型PXA的瘤体体积中位数为7.2cm3;无水肿或轻度水肿3例(27%),中度水肿7例(64%),实质型PXA恶变发生率为9%(1/11)。实质型PXA MRI表现为实性肿块(伴或不伴囊变区),多数形态规则,边界清楚,实质部分T1WI呈等、低信号,T2WI呈高信号,瘤周水肿较轻,增强扫描呈明显较均匀或不均匀强化,邻近脑膜一侧强化显著。结论:实质型PXA的病程较短,肿瘤体积较小,恶性程度较低,MRI表现有一定的特征性,手术切除预后较好。

Objective：To study the clinical,pathological and MR imaging characteristics of solid type pleomorphic xanthoastrocytomas（PXA）.Methods：The clinical and pathological materials of 23 cases with PXA were analyzed retrospectively,mainly concentrated on the location,size,peri-tumoral edema,incidence of malignant change as well as the MRI characteristics.Results：Of the 11 patients with solid type PAX,the mean age of onset was（32±9.7）y.The course of the illness in 9patients（81.8%）was less than one year.Tumor located in the temporal lobe（8cases,72.7%）and in insula（3cases,27%）.Cystic degeneration were seen in 8cases（72.7%）.The median of tumor volume was 7.2cm3.Peritumoral edema was absent or mild in 3patients（27%）and moderate in 7patients（64%）.The incidence of malignancy of solid type PXA was 9%（1/11cases）.MR imaging showed that most of the tumors were solid,with or without cystic area,mostly regular in shape,with well-defined boundaries.The solid components of tumors were isointense or hypointense on T1 WI,and hyperintese on T2 WI with heterogeneous enhancement after contrast administration.Marked adjacent leptomeningeal enhancement could be seen.Conclusion：Solid type PXA had a short course of illness;with small tumor size and low degree of malignancy,showing agood outcome after surgical excision.Certain MR imaging characteristics could be revealed.