Endoscopic Endonasal Approach for Clival Chordoma with Subarachnoid Invasion: A Two-Dimensional Step-by-Step Operative Video.

Chordomas are slow-growing, low-grade, locally invasive, and locally aggressive tumors. They peak at 40-60 years of age, with a male preponderance (2:1). Belonging to the sarcoma family and thought to develop from the notochord remnant, they are most commonly found in the midline, with half located at the sacrum and about one third at the skull base.