颅内血管外皮细胞瘤MRI误诊及原因分析

MRI Misdiagnosis of Intracranial Hemangiopericytoma and Analysis of the Causes

目的探讨颅内血管外皮细胞瘤(HPC)的MRI误诊原因,提高对该病影像诊断认识,以减少误诊率。方法回顾性分析3例MRI误诊但经病理证实的非典型颅内HPC患者临床及影像资料,并查阅相关文献,进行总结、分析。结果 3例均为单发病灶,周围片状水肿带。病例1为顶部镰旁体积较小类圆形肿块,呈等T1稍长T2信号,FLAIR高信号,增强扫描均匀明显强化,肿瘤内部可见迂曲血管影,术前诊断为血管瘤型脑膜瘤;病例2为颞枕部交界区分叶状肿块,呈混杂T1短T2信号,FLAIR为低信号,增强扫描边缘明显强化,其内见斑片状不强化区,邻近颅骨内板受累,信号异常,术前诊断为脑膜瘤;病例3为桥小脑角区类圆形肿块,以稍长T1长T2信号为主,其内可见多发细小分隔,FLAIR为高信号,增强扫描明显不均匀强化,边缘可见流空血管及囊变信号,术前诊断为听神经鞘瘤;3例病理证实均为颅内HPC。结论不典型颅内血管外皮细胞瘤极易误诊,但仔细分析其MRI表现的一些细微征象并结合临床资料可提示诊断。

Objective To analyze the causes of MRI misdiagnosis of intracranial hemangiopericytoma （ HPC）, and improve the diagnosis level of imaging on finding the disease, so as to reduce the rate of misdiagnosis. Methods The clinical data and imaging findings of 3 cases with MRI misdiagnosis of HPC were selected and retrospectively analyzed, and the related literatures were also reviewed. Results All the analyzed 3 cases had single tumor with patchy edema around. Case 1 had a small round mass nearby the cerebral falx, which showed equal T1 and slightly long T2 signal, hyperintensity on FLAIR, and enhancement scan showed homogeneous intense enhancement and tortuous vascular within tumor, the preoperative diagnosis for hemangioma meningioma ; Case 2 had a lobulated mass located in temporal occipital junction, which showed mixed T1 and short T2 signal, hypointensity on FLAIR, and enhancement scan shows obvious enhancement at the edge of the tumor, and there is no enhancement in the middle of region, with skull abnormal signal, the preoperative diagnosis for meningioma. Case 3 had a round mass located in cerebellopontine angle area, which exhibited slightly long T1 and long T2 signal, with multiple small separation, hyperintensity on FLAIR, and enhancement scan showed inhomogeneous enhancement, vascular flow void and cystic signal at the edge of the tumor, the preoperative diagnosis for acoustic neurinoma ; The 3 cases were intracranial hemangiopericytoma as confirmed by pathology. Conclusion Atypical intracmnial aneurysms are prone to misdiagnosis ; However, the diagnosis can be clearly prompted by carefully analysis of some minor signs in MRI performances and combined with clinical data.