A very large mass, which has destroyed the left inferolateral aspect of the clivus, extends laterally through the floor of the left middle cranial fossa as far as its lateral wall. It extends inferiorly through the destroyed floor into the infratemporal fossa and posteriorly impinges upon the pons immediately to the left of midline. It contacts the left side of the basilar artery, but does not appear to encase it. The left internal carotid artery is markedly displaced laterally, almost to the lateral wall of the left middle cranial fossa. It is totally encased by the tumour as it emerges from carotid canal, but remains patent. Posterolaterally it has invaded through the destroyed petrous bone to abut the left cerebellar hemisphere. It occupies the jugular bulb and abuts the left internal auditory meatus on three sides.
Conclusion: Very large extension of left sided "clival chordoma" to almost entirely occupy the anterior aspect of the left middle cranial fossa, a small portion of the posterior fossa and the upper portion of the left infratemporal fossa.