Angioarchitecture of intracranial hemangiopericytoma and its relation to intraoperative blood loss: a comparative study with angiomatous meningioma

Abstract

Objective To investigate the tumor angioarchitecture of intracranial hemangiopericytoma (HPC) and its relation to intraoperative blood loss.Methods 38 HPC-suspected cases by intraoperative pathology were originally included in this study.After intraoperative blood loss was assessed by the surgeon,the characteristics of tumor angioarchitecture were observed with silver staining and electron microscopic technique.The expression of vascular structural proteins was also studied by immunohistochemical and PAS dual staining.Results Lastly 22 cases satisfied the main criteria for HPC (vimentin+,EMA-) and angiomatous meningioma (vimentin +,EMA +) was diagnosed in 12 cases.There was not significant difference in tumor size and intraoperative urine volume between the two groups (P ＞ 0.05).However,both the blood loss and intraoperatively infused volume were increased and the operation duration was longer during HPC resection (P ＜ 0.05).Vascular endothelium and basement membrane were not intact,while vascular smooth muscle and reticular fibers were damaged and lost obviously in HPC.There were less α-SMA and more MMP-9 expression in HPC than that in angiomatous meningioma,although significant difference was not showed in microvessel density between the two groups (P ＞ 0.05).Conclusions Pathological remodeling and tumor cell invasion are obvious in HPC angioarchitecture,and this may play an important role in intraoperative blood loss in patients undergoing HPC resection. Key words: Hemangiopericytoma; Angiomatous meningioma; Blood loss ; Angioarchitecture