抄録
A 75-year-old male suffered sudden onset of retroorbital pain, visual loss, periorbital ecchymosis, and double vision without preceding trauma, paranasal sinus surgery, or infectious signs. Neuroophthalmological inspection also revealed marked restriction of the extraocular movements, visual defect, and exophthalmos on the affected side. Neuroimaging showed an irregular-shaped retrobulbar mass centered in the inferolateral aspect and partially protruding between the inferior and lateral rectus muscles without enhancement by contrast medium. High dose steroid therapy provided little improvement in the visual symptoms. Needle aspiration biopsy revealed only fluid hematoma. Surgical exploration via the lateral wall of the orbit resulted in escape of chocolate-colored, liquefied hematoma during dissection between the inferior and lateral rectus muscles. No obvious vascular lesion was recognized. A small purplish elastic soft mass with irregular contours was recognized adherent to the inferior rectus muscle within the capsule of the hematoma. The mass was subtotally resected. The histological diagnosis was inflammatory pseudotumor with hemorrhagic change. No component of vascular malformation was found. Visual function and extraocular movement improved postoperatively and neuroimaging showed no abnormal structures in the affected orbit. Pseudotumor may bleed and form a retrobulbar hematoma which carries the risk of visual loss.
