SOLITARY FIBROUS TUMOR OF THE ORBIT

PURPOSE: We studied a case of solitary fibrous tumor of the orbit in a 75-year-old man. METHODS: The patient had painless, slowly progressiv e proptosis of eight months' duration. He underwent magnetic resonance imaging, which showed a well circumscribed retrobulbar mass. The tumo r was excised. RESULTS: Examination of the tumor disclosed haphazardly arranged spindle cells alternating with collagenous, hypocellular are as in a richly vascular background without necrosis. Immunoperoxidase stains showed characteristic expression of CD34 and vimentin. CONCLUSI ON: Solitary fibrous tumor can infrequently involve the orbit and may recur locally and metastasize, necessitating long-term follow-up.