Ethmoidal synovial sarcoma presenting with epistaxis and nasal deformity: A case report.

Synovial sarcoma of the paranasal sinuses is an exceptionally rare malignant tumor, with only a few ethmoidal cases reported in the literature. We describe a 20-year-old woman presenting with recurrent epistaxis, rapidly progressive nasal obstruction, and external nasal deformity. Imaging revealed an aggressive ethmoidal mass with extension into the nasal cavity, orbit, and skull base, confirmed by histopathology and immunohistochemistry as synovial sarcoma. The patient underwent endoscopic endonasal resection followed by adjuvant radiotherapy. This case emphasizes the importance of including synovial sarcoma in the differential diagnosis of sinonasal tumors in young adults and highlights the role of multimodality imaging and pathology in guiding diagnosis and management.