Ewing's sarcoma family of tumors of the maxillary sinus: a case report of multidisciplinary examination enabling prompt diagnosis.

There have been approximately 10 reports in English literature of cases of Ewing's sarcoma family of tumors (EFT) arising in the maxillary sinus. In this location, some tumors mimic EFT, and are more frequently encountered. Herein, we present an additional case of an EFT originating in the maxillary sinus. The patient was a 15-year-old boy complaining of a non-tender swelling of the left cheek. Laboratory tests showed no abnormalities. Computed tomography and magnetic resonance imaging revealed a mass centered in the maxillary sinus with degeneration of the surrounding bones. Pathological examination along with flow cytometry and G-banding enabled the prompt diagnosis of EFT with the EWS/FLI1 fusion gene. The patient is planned to undergo chemotherapy. An origin in the head and neck and the presence of the typical EWS/FLI1, in conjunction with an opportunity for immediate treatment, may predict a relatively better prognosis for EFT in our case.