Clival Chordomas

Chordomas are rare midline primary bone tumors arising from notochord remnants mainly located in the clival or sacrococcygeal regions. Headache and diplopia due to a deficit of the VI cranial nerve are the most common symptoms at clinical onset. A major role in the treatment of chordomas is played by extensive surgical resection; post-operative high-dose radiotherapy using high-energy photons and charged particles seems to provide better tumor control. The selection of the best surgical approach should be tailored according to the size of the tumor and its anatomical location and extension. Since the dura is an essential barrier against the tumor, an extradural route should be chosen unless it is invaded by the tumor. Midline anterior approaches (microscopic, endoscopic or combined) provided access to the clivus taking advantage of an anatomical path of dissection free of major neurovascular structures and reducing parenchymal injury and intradural cranial nerve damage. Lateral skull base approaches are usually preferred in cases of tumors surrounding the internal carotid artery, intimately involving the cavernous sinus, the temporal bone, the vertebro-basilar arteries and the brainstem, because lateral routes allowed for a better surgical control on neurovascular structures, for an easier intraoperative repair of dural openings and for a better separation of the brainstem–tumor interface. Although chordomas are histologically benign lesions, they are associated with a high recurrence rate and with a poor prognosis. Patient age at onset of symptoms, pathological patterns, extent of resection and cytogenetic abnormalities are thought to influence the prognosis.