Intracranial hemangiopericytomas: correlation of topoisomerase IIalpha expression with biologic behavior.

Background: Meningeal hemangiopericytomas are aggressive tumors that have a high rate of recurrence despite gross total resection and radiation therapy. Topoisomerase, a cell proliferation marker, is also a target of certain chemotherapeutic agents, and its nuclear levels are speculated to predict efficacy of targeted therapy. The aim of this study was to correlate the topoisomerase IIalpha proliferation index (TPI) with biologic behavior in intracranial hemangiopericytomas.