Patient 1 was a 44-year-old female with a progressively enlarging orbital mass on the right side for 2 years, while patient 2 was a 25-year-old female who complained of protrusion of the right eye for 2 months. Both patients presented with exophthalmos and a palpable infraorbital mass without vision loss. Magnetic resonance imaging examination showed a well circumscribed circular orbital lesion, with hypointensity on T1 weighted image and heterogeneous hyperintensity on T2 weighted image, which could be significantly enhanced, in either eye. Both eyes were diagnosed as begin orbital tumor and received resection under general anesthesia. Intraoperatively, the distal end of the tumors was found to transmigrate to normal nerves and insert into the inferior oblique muscle. Combined with the pathological diagnosis of schwannoma and postoperative occurrence of mydriasis and inferior oblique muscle paralysis in both patients, it was confirmed that the two lesions were schwannomas originating from the branch of the inferior oblique muscle innervated by the oculomotor nerve.
例1为44岁右眼眶肿物渐增大2年女性患者，例2为25岁右眼球突出2个月女性患者。2例患者均表现为眼球突出，并可扪及眼眶下方肿物，无视力下降，MRI检查均显示眶内类圆形边界清楚占位，T1加权像低信号，T2加权像混杂高信号，增强后明显强化；均诊断为右眼眶良性占位病变，且在全身麻醉下行右眼眶肿物切除术。术中见肿瘤的远颅端移行为正常神经条索并进入下斜肌，结合术后组织病理学检查结果以及2例患者术后均出现瞳孔散大、下斜肌麻痹状态，证实肿物为起源于动眼神经支配下斜肌分支的神经鞘瘤。.