A Rare Case of Ewing Sarcoma of the Left Ethmoid Sinus With Orbital Extension.

BACKGROUND

Ewing sarcoma (ES) of the ethmoid sinus with orbital involvement in an adult is very rare, with 16 reported cases in the literature. Immunohistochemical studies show small blue round cells positive for CD99 and fluorescence in situ hybridization (FISH) testing reveals positivity for the EWSR1 gene.

METHODS

A 38-year-old male with a diagnosis of ES of the ethmoid sinus presented with left-sided periorbital pain and edema, rhinorrhea, and proptosis. The patient underwent neoadjuvant chemotherapy, surgical resection of the left skull base, and postoperative proton radiotherapy.

RESULTS

The patient tolerated chemotherapy, surgical resection, and adjuvant proton radiotherapy well with resolution of proptosis, diplopia, and pain. Due to local recurrence, he is currently undergoing adjuvant chemotherapy.

CONCLUSION

Our findings provide insight on the clinical presentation and appropriate management of extraosseous ES, specifically in the ethmoid sinus in the adult population.