An unusual cause of proptosis: orbital solitary fibrous tumor: case report.

Although solitary fibrous tumors are well-recognized tumors, they have only recently been described in the orbit. Although histopathological awareness of the lesion has been heightened recently because of the discovery of CD-34 immunoreactivity in solitary fibrous tumors, including orbital lesions, it remains unrecognized clinically as a cause of unilateral proptosis. Clinical awareness of the lesion is important, because benign and malignant forms of the tumor occur. The malignant forms pursue an aggressive course manifested by local invasion, recurrent growth, or metastases. The benign lesions are histologically banal and are cured by surgical excision. This case report describes unilateral proptosis caused by an orbital solitary fibrous tumor, which occurred in a 43-year-old woman. The tumor had a benign histomorphology and clinical course, with surgical excision being curative. In reviewing the literature on orbital solitary fibrous tumors, clinical awareness of the tumor as a cause of unilateral proptosis is emphasized.