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

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.