Solitary fibrous tumor of the orbit with extraorbital extension: Case report

OBJECTIVE AND IMPORTANCE: Solitary fibrous tumors (SFTs) are rare tumors of mesenchymal origin that typically arise in the pleura. Only 24 cases of SF Ts in the orbit have been reported, all located within the orbit and genera lly with a benign course. We report the first case of an orbital SFT with e xtraorbital extension and short-term regrowth. CLINICAL PRESENTATION: A 54-year-old man presented with proptosis and doubl e vision that had persisted for 7 months. The tumor extended from the right extraconal inferolateral orbit to the extradural middle cranial fossa and cavernous sinus, via the superior orbital fissure, on magnetic resonance im aging scans. Positron emission tomography with [F-18]fluorodeoxyglucose dem onstrated faint uptake in the orbital portion. INTERVENTION: Resection of the tumor was performed twice, because of short- term regrowth of the residual tumor in the orbit. The histological diagnosi s was a SFT. The MIB-1 labeling index was 7% and the mitotic count was 5 mi totic figures/10 high-power fields at the time of the second operation. The se findings indicate the malignant nature of the tumor. CONCLUSION: The natural history of SFTs of the orbit remains unclear, and t he importance of careful and continued follow-up monitoring of the tumor sh ould be emphasized.