Abstract
A 68-year-old female was admitted with a rare intraorbital subperiosteal hematoma manifesting as sudden orbital pain, progressive blepharoptosis, and diplopia. Computed tomography showed a biconvex high density mass in the superomedial part of the left orbit, which was recognized to be a subperiosteal hematoma intraoperatively. The eroded orbital roof between the frontal sinus and orbit was a result of mechanical compression by the mucocele. Infection extending into the orbit was important in causing the hemorrhage.
