Ultrasound findings in a patient with primary orbital hemangiopericytoma

A 20-year-old white male with a left superorbital mass and significant left proptosis was referred from his primary care physician. A and B scan ultrasound examination revealed a mass in the superonasal quadrant of the left orbit that demonstrated compression, encapsulation, internal vascularity and low internal reflectivity. Diagnosis of orbital hemangiopericytoma was confirmed histologically from frozen sections taken during surgical excision of the tumor.