A case report of rare isolated Ewing sarcoma of left maxillary sinus

Background Ewing sarcoma is a malignant round cell neoplasm and categorized as part of Ewing family tumor (EFT). Only 1-4% of all Ewing sarcomas are primarily located in the head and neck region and the isolated primary sinonasal sarcoma represents a rare entity. This case was reported due to its rarity and dilemma in diagnosis of recurrent post-treatment. Case presentation We report a rare case of isolated left maxillary sinus Ewing sarcoma, presented with frequent unprovoked epistaxis, nasal blockage, and rhinorrhea from the left nostril for more than 2 years. Histopathological and immunohistochemical studies performed on the tissue taken from the left nasal mass confirmed Ewing sarcoma. He responded well to the 9 cycles of chemotherapy, evidenced by regression of mass from repeated CECT. However, the post-treatment scan showed multifocal nodular mucosal thickening involving the medial, anterior, and lateral walls of the maxillary sinus with corresponding bony resorption of the medial wall, raising a suspicion of residual disease. As such, he underwent endoscopic medial maxillectomy, which intraoperative findings revealed mild thickening of normal mucosa within the left maxillary sinus and histopathological examination showed no evidence of malignant cell. He showed no signs of recurrence during subsequent follow-up. Conclusion As a conclusion, in a case of suspicious residual or recurrent disease detected post-chemotherapy, MRI is an option to differentiate between mucosal thickening and residual tumor. However, the role of surgical resection is equally important in assisting the tissue diagnosis and ensures a better local control, perhaps can increase the survival rate.