Spontaneous hemorrhage in an intraorbital arteriovenous malformation

Objective: To report the clinical findings and management of spontaneous hemorrhage in an unsuspected intraorbital arteriovenous malformation. Design: Interventional case report. Methods: Review of clinical findings, radiologic studies, and treatment of the patient. Results: A 75-year-old woman sought treatment for the rapid onset of severe proptosis. Orbital exploration of a 'mass' imaged on computed tomography scan and magnetic resonance imaging resulted in massive intraoperative hemorrhage. Subsequent arteriographic and histopathologic analysis confirmed an underlying orbital arteriovenous malformation. Conclusions: Spontaneous intraorbital hemorrhage from an arteriovenous malformation is extremely rare, but should be considered in the differential diagnosis of rapidly progressive proptosis. (C) 2000 by the American Academy of Ophthalmology.