Orbital solitary fibrous tumor: a clinicopathologic study from a Chinese tertiary hospital with a literature review

Abstract
Purpose: To report the clinical features, imaging manifestations, histopathology, and immunohistochemical features of several cases of orbital solitary fibrous tumors (SFTs) in a Chinese tertiary hospital, and to undertake a literature review of this rare disease. Methods: A non-comparative retrospective review of clinical presentations, imaging manifestations, histopathology, and immunohistochemical features as well as the management and disease outcomes of patients with orbital SFT was conducted along with a review of orbital SFT cases in the literature. Results: This study includes two male and two female patients, with an average age of 53 years. Common presentations among these patients included a palpable subcutaneous mass, swelling of the eyelid, proptosis, diplopia, and vision disturbance. Three patients (cases 2–4) underwent imaging scans. All patients had complete surgical excisions and the ­tissue was subjected to pathological analysis. One patient (Case 4) experienced a recurrence with malignant transformation and received a re-excision surgery and postoperative radiotherapy. All patients remain alive and well after a minimum follow-up of 12 months (range 12–34 months). Conclusion: Despite its rare occurrence, we suggest that the possibility of orbital SFTs needs to be considered when a painless, slowly growing orbital mass is identified. Typical characteristic magnetic resonance imaging features of orbital SFTs are iso- or hypointense signals on T1 and T2-weighted images, with marked enhancement. A positive cluster of differentiation 34 (CD34) staining is an important diagnostic clue favoring SFT. Some orbital SFTs are infiltrating, aggressive, or recur with malignant transformation. Therefore, regular long-term follow-up after complete excision is mandatory.