A Solitary fibrous tumor is a rare orbital neoplasm derived from mesenchymal cells. The neoplasm should be considered in differential diagnosis of any orbital tumor, and immunohistochemial analysis is important for correct diagnosis. The authors herein describe a case of a solitary fibrous tumor in addition to the findings of a literature review. Solitary fibrous tumors can develop from not only the lacrimal gland, but also orbital soft tissue. Until now, there has been no report of a solitary fibrous tumor arising from orbital soft tissue in Korea.

A 50-year-old man visited our clinic due to a slow progressing mass on the lateral side of the left eye for 1 year. The patient did not suffer from any discomfort or discharge from the mass. Slit lamp and other ocular examinations were unremarkable. Orbital MRI revealed a solid extra-conal enhanced mass that measured 13×11 mm adhering to the lateral wall of the left orbit. Total surgical excision was Performed under local anesthesia and tumor cells showed a strong and diffuse positivity for CD34 by immunohistochemistry. The findings were consistent with the diagnosis of orbital solitary tumor.

The orbital solitary tumor is rare, but it should be considered in the differential diagnosis of any orbital tumor.