Endoscopic transsphenoidal resection of a large chordoma in the posterior fossa.

Encouraged by an experience with endoscopic transsphenoidal pituitary surgery, an endoscopic transsphenoidal technique was applied in a patient with a large chordoma in the posterior fossa. The patient was a 40-year-old man with a two-year history of progressive ataxia, a memory disorder and emotional instability. A magnetic resonance (MR) scan of the brain revealed a midline posterior fossa mass measuring 4 cm in diameter located between the clivus and the brainstem. The basilar artery and its bifurcation were encased by the tumor and the brainstem was also distorted by the tumor. Obstructive hydrocephalus was treated previously with a ventriculoperitoneal shunt and fractionated external beam radiation treatment was given without histological diagnosis at another hospital. Subtotal resection of the tumor was achieved utilizing an endoscopic transphenoidal technique through the patient's nostril. The portion of the tumor located behind the basilar artery was not resected in order to protect the brainstem perforating arteries. The patient showed dramatic improvement of his symptoms postoperatively. Residual tumor located behind the basilar artery was treated by stereotactic gamma-knife surgery. This is the first reported case of a large posterior fossa chordoma being treated by an endoscopic transsphenoidal technique.