Anatomical correlates of endonasal surgery for sinonasal malignancies.

In recent years, endoscopic endonasal techniques have been applied to the treatment of sinonasal malignancies. Comprehensive anatomical knowledge is essential to preserve oncological principles and minimize surgical morbidity. The bones that form the anterior cranial base are pneumatized and the sinuses provide surgical corridors for the endoscopic endonasal approach to the skull base. During endoscopic endonasal resection of sinonasal malignancies, usually, the intranasal portion of the tumor is first debulked to provide visualization of the margins and assess the extent of the tumor. Afterwards the tumor is completely removed and the margins of resection are defined. In case of dural resection, the reconstruction is done with vascularized tissue (septal flap or pericranial flap). Sinonasal malignant neoplasms that invade the skull base can be resected accordingly to oncological principles using endoscopic endonasal techniques. Profound knowledge of the endoscopic anatomy of the ventral cranial base is paramount in order to perform a safe resection and reconstruction.