Extraosseous Ewing's sarcoma arising from the pterygomandibular space

Abstract

Extraosseous Ewing’s sarcoma (EES) arising in head and neck is extremely rare. We report on a rare case of EES originating from the pterygomandibular space. A 15-year-old boy was seen with a rapidly growing mass in the right upper neck, difficulty in opening mouth, dysphagia, numbness in the right lower lip and buccal skin. Clinical and radiological examinations indicated that a soft tissue mass origi-nated from the pterygomandibular space with the submandibular space and mouth floor extension. Histological and immunohistochemical evaluations of the biopsy specimen revealed poorly differentiated small blue round cells with positive stains for CD99 and neuron-specific enolase. According to the clinical manifestation, CT and MRI findings, histological pattern and the results of the immunohistochemical studies, the final diagnosis was EES. Our patient was treated with chemotherapy and radiotherapy. The lesion recurred locally after 10 months and he died of multiple distant metastases 22 months later. Early and confident diagnosis coupled with combined surgical excision and modern chemotherapy/radiotherapy appears to be the most effective treatment plan.