Due to the insidious onset and common symptoms, the diagnostic of sinonasal tumors is late in the evolution. Usually, at that time, the preferred endoscopic approach alone is not recommended, therefore a mixed openendoscopic approach appears to be the best choice in terms of exposure of the tumor and a clear margin resection. The purpose of this case report study is to demonstrate the necessity of careful preoperative assessment and the advantages of combined approach for a complete resection and favorable long-term results.