Primary orbital low-grade fibromyxoid sarcoma - A case report.

An 18-year-old female presented with rapidly progressive proptosis of the left eye for one month and grade II relative afferent pupillary defect. Orbital imaging showed a well-defined homogenous extraconal mass in close relation to the lateral rectus muscle and extending up to the superior orbital fissure, associated with bony erosion. An incisional biopsy was performed, with the histopathology demonstrating stellate to spindle-shaped tumor cells (fibroblasts) embedded in a richly myxoid matrix. A diagnosis of low-grade fibromyxoid sarcoma (LGFS) was made. The patient was treated by stereotactic external beam radiotherapy. Here, we report a case of LGFS which, to the best of our knowledge, is the first at an orbital location.