Masson tumor is a benign vascular lesion characterized by an intravascular papillary endothelial hyperplasia. Peri orbital locations are rare. We report a case of Masson tumor localized in the upper internal angle of the left orbit revealed by progressive ocular proptosis. Orbital computed tomography (CT) scan and magnetic resonance imaging (MRI) showed a vascular mass in the left internal canthus mimicking an arterioveinous malformation. The patient underwent total removal of the lesion with a favorable postoperative follow up. Histological examination found an intravascular papillary endothelial hyperplasia without atypical features corresponding to Masson tumor. A thorough literature review of Masson tumor is presented with a discussion of clinical findings and management.