Magnetic resonance imaging findings and pathological features of intracranial hemangiopericytoma

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. Key words: Central nervous system neoplasms; Hemangiopericytoma; Magnetic resonance imaging; Pathology; Immunohistochemistry