Solitary fibrous tumor of the orbit: a clinicopathologic study of six cases with review of the literature.

Solitary fibrous tumor of the orbit is a rare spindle cell neoplasm. There are 42 cases of solitary fibrous tumor of the orbit available in the literature. We present six more cases of orbital solitary fibrous tumors, which presented to our institute between 1999 and 2001. We highlight the need for clinical recognition of these tumors as a distinct entity and inclusion of this tumor in the etiological differential diagnosis of well-circumscribed orbital lesions presenting as unilateral proptosis in both children and in adults. The diagnosis may be suspected based on radiological features supported by histopathologic and immunohistochemical study. The strong CD34 immunoreactivity of this tumor supports its diagnosis. Complete surgical resection is the most important prognostic factor of this tumor.