桥小脑角硬膜内上皮样囊肿的诊断和显微外科治疗

INTRADURAL EPIDERMOID CYSTS OF THE CEREBELLOPONTINE ANGLE: DIAGNOSIS AND MICROSURGERY

①目的 探讨桥小脑角硬膜内上皮样囊肿的诊断及显微外科治疗。②方法 对 4 2例经显微手术治疗的桥小脑角硬膜内上皮样囊肿进行回顾性分析 ,所有病人均行颅脑CT及MRI扫描 ,并分析其影像学特征。③结果 桥小脑角上皮样囊肿CT表现为低密度占位性病变 ,MRI检查T1 WI表现为低信号 ,T2 WI表现为高信号 ,DWI表现为明显高信号 ,边缘不规则、锐利 ,周围无水肿 ,病变无强化。本组 4 2例 ,全切除 36例 ,全切除率 85 % ,Ⅰ型全切除率 91 % ,Ⅱ型全切除率 6 0 % ,Ⅲ型全切除率 6 6 %。④结论 桥小脑角硬膜内上皮样囊肿的诊断主要依靠颅脑CT及MRI扫描 ,特别是DWI序列呈明显高信号 ,可以和蛛网膜囊肿相鉴别。治疗主要依靠显微外科手术治疗。Ⅰ型病变全切除率较高 ,Ⅱ、Ⅲ型病变全切除率较低 。

Objective To discuss the diagnosis and microneurosurgery of intradural epidermoid cysts (ECs) of the cerebellopontine angle(CPA). Methods A retrospective analysis of 42 patients with intradural ECs in the CPA was carried out. All patients were investigated with cranial CT and MRI, their characteristics of the images analyzed. Results On CT, ECs appeared as a low density space occupying lesion, sharply delineated. T 1 weighted images showed low signal, T 2 weighted images, a very bright signal intensity, and diffusion weighted MR(DWI) was different from that produced by cerebrospinal fluid. In which, 36(85%) of 42 cases were totally resected. The total resection was 91%, 60%, and 66% for patients with Type Ⅰ, Type Ⅱ, and Type Ⅲ, respectively. Conclusion Diagnosis of intradural ECs in the CPA depends mainly on cranial CT and MRI, especially DWI. On DWI, ECs shows markedly bright signal intensity, while arachnoid cysts shows low signal intensity. The treatment of intradural ECs in the CPA is primarily microsurgery. Type Ⅱ and Ⅲ are more difficult to be resected radically than Type Ⅰ. Total resection of the tumor should be performed as possible on the basis of the preservation of intact vascular and neural structures.