Biphasic solitary fibrous tumor of the orbit with distant metastases.

The aim of this study is to report the first case of biphasic solitary fibrous tumor (SFT) of the orbit with documented histological transformation and metastatic diffusion. We describe a case of a 23-year-old Caucasian man with recurrent SFT of the right orbit with intracranial invasion. The patient underwent surgical tumor removal via a right fronto-orbital approach. Histopathological examination showed a biphasic tumor pattern with both spindle cell and epithelioid components. The histopathological re-evaluation of previously removed lesions (1999 and 2004) confirmed the diagnosis of SFT, without any evidence of epithelioid component at that time. The patient developed local recurrence and systemic metastases (occipital foramen and clivus, paravertebral muscles and peritoneum) three years after surgery. We are unaware of previous reports of biphasic solitary fibrous tumor of the orbit with documented histological transformation and metastatic diffusion.