Endoscopic transnasal approach for orbital tumors: A report of four cases.

Endoscopic transnasal approach is an excellent technique for resecting orbital tumors located inferiorly and/or medially to the optic nerve. The aim of this study was to present four cases of orbital tumor which were, at least in part, resected by an endoscopic transnasal approach and to discuss both indications and limitations of this approach through a comparison of the location and tumor status, including the pathology, of these cases. In two cases with orbital tumor located in a medial-inferior quadrant, we were able to resect it only by an endoscopic transnasal approach. Because we experienced transient diplopia and dyschromatopsia after resecting intraconal tumors, a careful choice for the best approach is suggested in view of the location, size and properties of the tumor. In the third case, with tumor located in an inferior-lateral quadrant, it was eventually resected using a frontal-zygomatic approach because the medial and inferior borders of the tumor could not be identified and the lateral border was beyond the limits of manipulation by an endoscopic transnasal approach. In the last case with possible malignant tumor adhered to the lateral vital, the tumor was resected using a transantral approach. Based on these experiences, we introduce the indications for an endoscopic transnasal resection of orbital tumors.