颅内间变型血管周细胞瘤的MRI诊断

MRI Features of Intracranial Anaplastic Hemangiopericytoma

目的探讨间变型血管周细胞瘤(AHPC)的MRI影像学表现,以提高其诊断准确率。方法回顾性分析8例经手术病理证实的AHPC患者的临床、病理及MRI资料。结果肿瘤呈分叶状(6例)、不规则形(1例)、跨叶生长(1例)。MR平扫T1WI呈等、稍低信号6例,混杂信号2例;T2WI呈等、稍高信号6例,混杂信号2例;增强扫描肿瘤实性部分均明显强化;明显囊变坏死4例,"脑膜尾征"2例,相邻颅骨破坏1例,瘤周水肿明显4例,7例与硬脑膜以相对窄基底相连。所有病例内部及周边均可见数量不等的血管影。结论 AHPC具有明显的分叶状、跨叶生长倾向,肿瘤易出血、囊变、坏死,"脑膜尾征"少见,易破坏邻近颅骨,瘤周水肿明显等特点,但需与恶性脑膜瘤及WHOⅡ级血管周细胞瘤相鉴别。

Objective To analyze the MRI features of anaplastic hemangiopericytoma （AHPC） in the central nervous, and to improve the diagnostic accuracy. Methods The MR images and clinical data of 8 cases of anaplastic hemangioperi- cytoma proved by pathology and operation were analyzed retrospectively. Results The tumors showed lobulated shape in 6 cases, irregular shape in 1 and invaded adjacent lobe in 1. 6 lesions displayed iso or hypo intense signal on Tl WI and iso or hyper intense signal on T2WI. 2 lesions showed heterogeneous intense signal on TIWI and T2WI. After contrast injec- tion, the solid part of tumors showed marked heterogeneous enhncement in all cases. Significant necrosis and cystic changes were seen in 4 cases, and the ＂dural tail sign＂ was found in 2 cases. 1 case had bony destruction, and 4 cases showed sig- nificant peritumoral edema. 7 cases connected to the narrow base of dura. vessels were observed in all masses. Conclu- sion MR imaging findings of intracranial anaplastic hemangiopericytoma include lobulated shape, invaded adjacent lobe, easily bleeding, necrosis and cystic changes, rare ＂dural tail sign＂, damage adjacent skull, and significant peritumoral e- dema. Even so, some cases still should be differentiated from malignant meningioma and WHO Ⅱ HPC.