Chordoma and chondrosarcoma of the skull base. A series of 24 surgically treated cases and factors predicting early tumor recurrence

Chordomas and chondrosarcomas (CC) of the skull base are rare accounting for 0.1-0.2% of all intracranial tumors. These neoplasms represent a challenge for the neurosurgeon because of their proximity to vital neurovascular structures. Although CC are generally regarded as slow-growing tumors, shortterm recurrencies after surgical treatment are not uncommon. However, the pathological features that have yet been investigated are poor predictors of outcome. We have retrospectively analysed a series of 24 patients with CC of the cranial base (14 males, 10 females; age 17-84 years) who were surgically treated at our institution since January 1988. Tumor location was as follows, upper clivus 4 cases, middle clivus 13, lower clivus 4, and petrous bone 3. The tumor extended to the anterior skull base and orbit in 2 cases and to C1-C2 in 4. The cavernous sinus was involved in 6 cases. In one case, the tumor was primarily retropharyngeal in location and infiltrated the clivai bone at a later stage. One case also had a vertebral chordoma at the thoracic level, another case developed pulmonary métastases. A total of 40 surgical procedures were performed, that included transsphenoidal approaches 22, trans-maxillary 5, extreme lateral (EL) 4, extended subfrontal 2, orbito-zygomatic 2, trans-oral 2, suboccipital 1, fronto-temporal 1, combined subtemporal-infratemporal and EL 1. Total removal (absence of tumor on microsurgical inspection and on MRI at 3 months after surgery) was achieved in 9 cases. In 10 cases, a subtotal removal was done (resection of 80% of tumor), and in 5 cases the tumor was partly removed (resection