微囊型脑膜瘤的MRI表现及病理基础

MRI manifestations and pathological basis of microcystic meningioma

目的:探讨微囊型脑膜瘤的MRI表现及病理基础。方法:回顾性分析16例经手术病理证实的微囊型脑膜瘤的影像资料,将其MRI表现与病理基础进行对照分析。结果:肿瘤位于大脑凸面12例,大脑镰旁4例。11例表现为边界清楚的、以囊性为主的软组织肿块;肿块在T_1WI上呈等或低信号,T_2WI上呈高信号,瘤内可见多发分隔影,周围水肿较轻;增强扫描肿瘤呈细网状强化。5例误诊为非典型脑膜瘤(3例)和血管瘤型脑膜瘤(2例),表现为边界清楚的实性软组织肿块,肿瘤内囊变坏死少见。病理上,肿瘤内部可见多发类似细筛状结构(即微囊),可与MRI表现相对应。结论:通过与病理基础的对照分析,可更深入的认识及理解微囊型脑膜瘤的MRI表现,从而有助于提高该肿瘤的术前定性诊断。

Objective:To explore the MRI manifestations and pathological basis of microcystic meningioma.Methods:Data of 16 patients with pathologically confirmed microcystic meningioma by surgery were retrospectively analyzed,including MRI findings and pathological basis.Results:Twelve cases were located in the cerebral convexities and and 4 cases were located in the beside cerebral parafalx.Eleven cases demonstrated as well-defined and predominantly cystic soft tissue masses with multiple separations and mild surrounding edema,showing equal or low signal on T 1WI,high signal on T 2WI,and finely reticulated enhanced after contrast enhancement.5 cases were misdiagnosed as the atypical meningiomas(3 cases)and hemangioma type meningioma(2 cases),which demonstrated as well-defined solid soft tissue masses,rarely with cystic degeneration or necrosis.Pathologically,multiple sieve-like structures(microcapsules)could be seen in the tumor,which corresponded with MRI manifestations,including 3 cases of atypical meningioma,2 cases of hemangioma type meningioma.Conclusion:Through the correspondence analysis with the pathological basis,the MRI manifestations of microencapsulated meningiomas can be better understood,which helps to improve the preoperative qualitative diagnosis of the microcystic meningioma.