少见部位血管外皮细胞瘤的影像学表现

目的探讨少见部位的原发性血管外皮细胞瘤（hemangiopericytoma,HPC）的影像学表现,以提高对该病的认识。方法回顾性分析经病理证实的9例HPC的临床及影像学资料。结果 9例HPC中,位于颅内6例,筛窦1例,肺2例。6例颅内HPC中,2例为复发病灶。6例均边界清晰,5例呈分叶状,1例呈类圆形。4例信号不均匀,其中3例可见明显坏死囊变区。T1WI呈等、稍低信号;T2WI呈等、稍高信号,增强扫描6例均呈明显强化。5例瘤内可见血管流空信号。5例以窄基底与硬脑膜相连,1例以宽基底相连。6例均未见＂脑膜尾征＂,邻近骨质均未见明显破坏征象。1例筛窦病灶形态不规则,分叶不明显,密度不均匀,增强扫描明显强化,受累骨质呈溶骨性骨质破坏。2例肺部病灶,均表现为肺内单发病灶,边界清晰,未见分叶,密度均匀,增强扫描强化明显,未见明显浸润征象及远处转移。结论原发于颅内、鼻腔鼻窦及肺部少见部位的血管外皮细胞瘤的影像学表现有一定的特征性,熟悉其表现有助于提高在少见部位对该病诊断的准确率。

Imaging Features of Primary Hemangiopericytoma (HPC) in the Rare Site

Objective To investigate the imaging features of primary hemangiopericytoma（HPC） in the rare site, and to improve its diagnostic accuracy. Methods Clinical data and CT or MR imagings of 9 cases with histologically proved HPC were retrospectively reviewed. Results 6 of 9 lesions were located in intracranium, 1 in ethmoidal sinus and 2 in lung. 2 of 6 intracranial HPCs were recurrent lesions. All 6 cases were welldefined, 5 cases showing multilobulated and 1 round in shape. Tumors manifested as iso-intensity, slight hypo-intensity on T1 WI, iso-intensity, slight hyper-intensity on T2 WI and all 6 lesions showed marked enhancement with contrast-enhanced scans. 4 of 6 lesions were heterogeneous with presence of cystic degeneration areas in 3 lesions. Flow empty vessels were present in 5 lesions. 5 cases had narrow-based dural attachment and 1 had broad-based attachment. None had erosion or hyperostosis in the adjacent bone and none had dural tail sign. Lesion in ethmoidal sinus manifested as irregular soft tissue mass without obvious lobulation, heterogeneous density and marked enhancement on contrast-enhanced CT scan. Osteolytic obstruction with mild bone swelling was seen in the involved bone. All 2 cases in the lung manifested as solitary tumors. On plain CT scans, the tumors were homogeneous, well and sharply circumscribed with apparent enhancement on contrast-enhanced CT scan. Adjacent lung tissue invasion and distant metastasis could not be seen. Conclusion The imaging findings of primary HPC in the rare site including intracranium, lung, nasal cavity and para-nasal sinus were found with certain characteristics. Familiar with these features of the lesion in rare sites may improve accuracy of its diagnosis.