Imaging diagnosis of intracranial hemangiopericytoma

YAO Qian-dong; YANG Chun; ZHANG Jing-song; ZHENG Min-wen

Abstract：Objective To explore the imaging features of intracranial hemangiopericytoma (HPC) and to improve the di-agnosis of the disease .Methods The imaging appearances and pathological data of 26 cases of intracranial HPC proved by pathology and operation were analyzed retrospectively .Results All the intracranial tumors of 26 patients were located in-side the skull and outside the brain parenchyma ,including that 7 tumors were located in the skull base ,5 in sagittal sinus surface ,4 in cerebral falx ,3 in tentorium cerebelli and 7 in brain convexity .15 tumors had lobulated appearance and 11 tumors were irregular shape .On CT ,the tumors were manifested as isodensity or slightly high density (n=7) and slightly hypodense (n=3) .4 cases showed bony destruction ,1 case had calcification .After contrast injection ,homogeneous en-hancement was seen in 4 cases and inhomogeneous enhancement in 6 cases .On MRI ,the lesions were shown heterogeneity (n=20) or slightly hypointense (n=3) or slightly hyperintense (n=3)on T1 WI ,mixed high-low signal (n=18) or iso-low signal (n=5) or iso-signal (n=3) on T2 WI .cystic degeneration (n=21) ,blood vessel flow void phenomenon (n=18) ,hemorrhage (n=7) and bony destruction (n=4) were shown on both T1 WI and T2 WI .After contrast injection ,in-homogeneous enhancement was seen in 22 cases and uniform enhancement in 4 cases .17 cases showed significant peritu-moral edema .Pathology showed tumor cells were diffusely distributed .The stroma had large number of slit-like vascula-ture .Immunohistochemical examination showed CD34 ,vimentin and CD99 expression ,and CD31 ,epithelial membrane antigen ,cytokeratin ,synaptophysin and Bcl-2 showed no expression in all 26 cases .Conclusion The imaging findings of HPC have certain characteristics ,which are helpful for suggesting the diagnosis .It should be differentiated with meningio-ma .Some malignant appearance should be observed carefully in order to improve the correct diagnostic rate .