Figure 2:

Intraoperative neuroendoscopic findings. (a) The clivus becomes visible after the nasal pharyngeal membrane is detached caudally. (b) The yellowish tumor lesion is identified lateral to the clivus and dorsal to the longus capitis muscle. (c and d) Views using a neuroendoscope angled at 30°. After subtotal resection of the tumor, the dura of the petrous bone and the inner wall of the internal auditory canal are exposed. The tumor invading the hypoglossal canal (white arrow) is also removed. (C: Clivus; IAC: Internal auditory canal; LoCapM: Longus capitis muscle; NasPhM: Nasal pharyngeal membrane; PetD: Dura of the petrous bone; T: Tumor).