Primary orbital low-grade fibromyxoid sarcoma - A case report

Abstract

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.

Keywords: Fibromyxoid; orbit; sarcoma; soft tissue tumor.

Figure 1

Primary orbital low-grade fibromyxoid sarcoma in an 18-year-old patient. (a) External photograph in a worm's-eye view illustrates a left-sided proptosis. (b) Computed tomography (CT) orbit axial section shows a well-defined homogenously hyperdense apical mass lesion along the lateral rectus extending till the superior orbital fissure. (c) Histopathologically, the tumor showed alternating hypocellular, myxoid, and collagenous areas with stellate to spindle-shaped, bland appearing cells (HE × 20). (d) On immunohistochemistry, CD34 staining was positive. At 41 months post-EBRT, (e) external photograph in a worm's-eye view shows resolution of proptosis and (f) CT orbit demonstrates residual thick scar, the size of which has remained stable for over 24 months