[Diagnosis and treatment of orbit solitary fibrous tumor: a report of 4 cases].

OBJECTIVE: To investigate the diagnosis, treatment and prognosis of orbital solitary fibrous tumor. METHODS: Clinical data of 4 cases with orbital solitary fibrous tumor from January 2001 to June 2014 in the Second Affiliated Hospital of Xi'an Jiaotong University was retrospectively analyzed and the image, pathologic and immunohistochemical findings were reviewed. RESULTS: In the 4 cases, 3 were males and 1 was female, aged from 48 to 67 years. The main symptoms were unilateral progressive proptosis, orbital tumor and decreased vision. Two cases involved the left orbit and 2 in right. The locations of the tumor were in the lateral (2 cases) or inferior orbit (2 cases). Encapsulated smooth round shadow was shown in imaging examination and a homogeneous enhancement strengthening was seen by CT scanning. All cases underwent surgical resection and the removed tumors, appeared as round or irregular oval with fibrous capsule, were 1.5-5.0 cm in size. Three cases were pathological benign and 1 was malignant. Microscopically, the tumors were composed of a large number of spindle tumor cells and varying amounts of interstitial collagen deposition and angiogenesis. There was no atypia in benign tumor, while there was atypia in malignant tumor. Moreover, the tumor was invasive, capsuleless and shown hyperplasia area by light microscope in the case with malignant disease. CD34 and Vimentin were positive in 4 cases and Bcl-2 positive in 2 cases by immunohistochemistry staining. One patient with malignant pathology showed strong positive staining of Ki-67 (>70%) and died of tumor recurrence 10 months after he received the second operation. No metastasis or recurrence occurred by a follow-up of 2 months to 5 years in other 3 cases. CONCLUSIONS: Orbital SFT is characteristic of unilateral progressive proptosis in symptom. Imaging examination is an important diagnostic tool and a complete surgical resection of the tumor is the primary treatment method. Diagnosis depends on pathological and immunohistochemical staining. Malignant transformation may be occurred from benign lesion, hence postoperative follow-up is essential for confirmed patients.(Chin J Ophthalmol, 2016, 52: 268-272).