The Whole Lateral Type of the Sphenoethmoidal Cell and Its Relevance to Endoscopic Sinus Surgery

Background: The sphenoethmoidal cell and the sphenoid sinus (SS) show great similarity in endoscopy and imaging. Hence, it is important to accurately identify the sphenoethmoidal cell preoperatively to prevent injury of the nerve and artery during endoscopic surgery. The aim of the present study was to investigate a special type of sphenoethmoidal cell. Methods: A total of 365 inpatients whose paranasal sinus computed tomography (CT) was collected and reviewed from May 2018 to September 2019 were included. The anatomical imaging characteristics of the sphenoethmoidal cell were observed. Results: A special type of the sphenoethmoidal cell was found on 9 sides in 730 sides (1.3%), according to its extension to the SS. Unlike Onodi cell (49.6%) and Jinfeng cell (1.3%), this cell simultaneously extends toward the superolateral, lateral, and inferolateral regions of the SS and is simultaneously closely attached to the optic canal and the maxillary nerve. Presently, this cell is named as the whole lateral type of the sphenoethmoidal cell, and the SS is located at the medial or inferomedial of it. Conclusions: When evaluating the paranasal sinus CT preoperatively, attention must be paid to the possibility of the whole lateral type of sphenoethmoidal cell appearing, not just Onodi cell, extending into the SS.