颅内血管周细胞瘤的磁共振影像学征象和病理学特点

Magnetic resonance imaging findings and pathological features of intracranial hemangiopericytoma

目的探讨颅内血管周细胞瘤的MRI影像学征象及病理学特点，以提高对本病的认识。方法回顾性分析南方医科大学南方医院2011年1月至2014年10月经手术病理证实的12例颅内血管周细胞瘤的临床特点、影像学表现、术中所见及病理特征。结果12例患者的影像学特征：肿瘤分叶状12例，7例肿瘤跨叶或跨线生长，9例可见水肿影，无出血及钙化征象，8例可见坏死囊变，11例可见血管流空影，增强扫描9例不均匀强化，8例窄基底与硬脑膜相连，5例可见脑膜尾征，1例邻近骨质破坏。所有患者均行手术切除，其中9例侵犯邻近组织，10例全切除，2例次全切除。术后病理诊断为颅内血管周细胞瘤WHOⅡ级5例，Ⅲ级5例，Ⅱ-Ⅲ级2例。免疫组化检测：CD34、Vim表达阳性；EMA、S-100、GFAP表达阴性；Ki-67阳性指数随着肿瘤级别的升高而增加。结论颅内血管周细胞瘤术前极易误诊为脑膜瘤，但其恶性程度高、预后差，其MRI影像学及病理学具有一定的特征性，分析总结其特点有助于提高诊断的准确率，为临床选择治疗方案提供帮助。

Objective To investigate magnetic resonance imaging and pathological features of intracranial hemangiopericytoma in order to improve the understanding of this disease. Methods From January 2011 to October 2014, the clinical features, imaging findings, intraoperative findings and pathologic features of 12 patients with intracranial hemangiopericytoma confirmed by surgical pathology in Nanfang Hospital, Sounthern Medical University were analyzed retrospectively. Results The imaging features of 12 patients： the tumors of all 12 patients were lobulated, 7 had cross-lobe or cross-line growth, 9 showed edema shadow. No hemorrhage and calcification were observed. Necrotic cystic changes were observed in 8 cases, vascular flow voids were observed in 11 cases. Enhanced scan revealed inhomogeneous enhancement in 9 cases. The narrow base connected to the dura in 8 cases. The dural tail signs were observed in 5 cases. The adjacent bone was destructed in 1 case. All patients underwent surgical resection, including 9 invaded the adjacent tissues, 10 were totally resected, and 2 were subtotally resected. Five patients were pathologically diagnosed as intracranial hemanyiopericytoma WHO grade II after procedure, 5 were diagnosed as grade III, and 2 were diagnosed as grade II-III. Immunohistochemical showed that the expressions of CD34 and Vim were positive, and those of EMA, S-100, and GFAP were negative. The Ki-67 positive index increased with the tumor grade. Conclusions Intracranial hemangiopericytoma is easily misdiagnosed as meningioma before procedure, however its degree of malignancy is high and the prognosis is poor. Its MRI and pathology have certain characteristics. Analyzing and summarizing its characteristics contribute to the improvement of the accuracy of preoperative diagnosis and provide to help for choosing clinical treatment options.