颅内幕上异位室管膜瘤的影像学研究

Imaging study of intracranial supratentorial ectopic ependymoma

目的分析幕上异位室管膜瘤的影像学特点及临床特点。方法经手术病理证实的幕上异位室管膜瘤24例,回顾性分析其影像学表现。结果幕上异位室管膜瘤有如下影像学特点:肿瘤多数起源于脑实质(16/24),少数起源于脑膜(8/24),多数位于大脑凸面(15/24),均为不规则多分叶状(24/24);在CT像表现为低等高(10/19)或低等(4/19)或等高(5/19)混杂密度,瘤内均可见钙化;在T1WI上表现为低等高(9/17)或低等(8/17)混杂信号,在T2WI上表现为低等高(11/17)或等高(6/17)混杂信号,以不均匀强化为主(16/17);囊性变多见(22/24);无复发,偶有转移(2/24)。肿瘤体积较大,平均最大径65 mm。患者主要为儿童和年轻的成人,临床病史较短(5个月)。结论幕上异位室管膜瘤有比较典型的影像学特点,结合临床表现有助于其术前正确诊断。

Objective To study the imaging findings and clinical features of supratentorial ectopic ependymoma. Methods The imaging findings of 24 pathologically proved cases of ependymomas were retrospectively reviewed. Results Supratentorial ectopic ependymoma had the following imaging characteristics： 2/3 of tumors located in the brain parenchyma （16/ 24）, 1/3 located in the meninges （8/24）, all tumors were irregular multilobulated （24/24） ; on CT examinations, tumors showed mixed low, iso and high density （10/19） or mixed low and iso density （4 /19） or mixed iso and high density （5/ 19）, calcifications were visible in all tumors; mixed low, iso and high signal intensity （9/17） or mixed low and iso signal intensity （8/17） on Tx WI, mixed low, iso and high signal intensity （11/17） or mixed iso and high signal intensity （6/17） on T2WI, most tumors had heterogeneous enhancement （16/17） and cystic change or necrosis （22/24） ; no recurrence occured, metastasis occasionally occured （2/24）. Tumors had large size, the average maximum diameter was 65 mm. The patients were mainly seen in children and young adults, course of disease was relatively short （5 months）. Conclusion Supratentorial ectopic ependymoma had typical radiographic features, which was helpful for its correct preoperative diagnosis combined with clinical manifestations.