Malignant peripheral nerve sheath tumor of the orbit: case report and literature review

Abstract

A 68-year-old woman with progressive visual loss and exophthalmos in her right eye had been operated on for a mass in her right calf 3 years earlier. Imaging showed a huge mass invading the orbital structures and temporal pole. The presumptive diagnosis was a malignant orbital tumor. The tumor was resected totally and eroded tissues such as the lateral rectus muscle and dural compartments were repaired. The histological diagnosis was a malignant peripheral nerve sheath tumor (MPNST). The patient recovered uneventfully and was discharged 8 days after surgery. Two years later she died from a liver tumor. Few MPNSTs involving the orbit have been reported.

Figure 1

(A) Prominent exophthalmos, chemosis, and flashing in the palpebras in the patient's right eye. (B) T1-weighted MRI showing the lesion originating from the lateral part of the orbit.

Figure 2

(A) Malignant tumoral cells and infiltrated tissue of the lateral rectus muscle (hematoxylin and eosin (H&E), × 400). (B) Mixoid changes are visible (H&E, × 100). (C) Rounded and ovoid cells include dense vascular and high mitotic activity (H&E, × 100).

Figure 3

(A) Postoperatively, the patient had no obvious cosmetic problems and deviation of her eye resolved. (B) Postoperative computed tomography showed no residual mass in the orbit 6 months after surgery. The repaired lateral rectus muscle appears normal.