Unusual Extraosseus Location of Ewing's Sarcoma: Case Report

Introduction: Extraskeletal Ewing sarcoma is a very rare malignant tumor. The head and neck region is an unusual primary location for this type of tumor 1. Clinical case: We present a 13-year-old girl with no known personal history. She was brought for consultation in June 2023 presenting a tumor mass in the left nasal fossa that caused slight nasal obstruction. She reported episodes of epistaxis and left epiphora, and denied any history of trauma to the facial region or some type of viral or catarrhal infection. During the physical examination we found a solid, elliptical mass between the body of the malar bone and the anterosuperior part of the left maxillary bone. There was a boundary between the lesion and the surrounding muscle and it did not infiltrate the skin. Discussion: Ewing sarcoma is the second most common malignant bone neoplasm in pediatrics; however, it is uncommon in soft tissues with a low incidence rate of 1.1%, including sinonasal SE, not to mention primary neuroectodermal tumors, which are tumors of small, round cells derived from soft tissue, and which belong to the Ewing sarcoma family 6. Conclusion: Ewing's sarcoma is a rare tumor; it usually occurs in children and young people with highly aggressive behavior and spreads rapidly and extensively. The presence of small round blue cells plus the immunohistochemical study confirms the diagnosis. For treatment there is still no consensus and universally accepted protocols, however, a multidisciplinary approach is required, with an aggressive approach combined with surgery and radio-chemotherapy. The good general condition of the patient at the time of diagnosis was very favorable in his response to oncological treatment and evolution; one year after diagnosis and initial management, no clinical or imaging signs of tumor persistence or recurrence were found.