Case of Ewing's sarcoma misdiagnosed as a periapical lesion of maxillary incisor.

Ewing's sarcoma (ES) belongs to the group II neuroectodermal tumors. They usually occur in diaphyses of long bones, ribs, and pelvis and are rare in head and neck bones, with only 30 cases reported. The mandible is more affected than the maxilla. ES is also the second most common primary malignant bone tumor found in children, after leukemia and osteosarcomas, but they are rare in adults. The following is a report of a new case of ES localized in the maxilla occurring in a 25-year-old man who had been misdiagnosed with an odontogenic infection. The patient was treated successfully, with a 2-year follow-up, by using a combination of aggressive systemic chemotherapy and surgery with primary reconstruction of the defect, avoiding the use of radiotherapy.