Chondrosarcomas of the skull base: review of the literature and report of two cases.

Chondrosarcomas are malignant mesenchymal tumours occurring only rarely in the bones of the cranium. Less than 5% of all chondrosarcomas are located in the head and neck area and their commonest location is the ethmoids and the sphenoid sinus. They are slow-growing tumours with low malignancy rate and unclear histopathogenesis. The prevailing hypothesis is that they arise from cartilaginous remnants in the petro-clival, spheno-occipital and fronto-nasal synchondroses. Diagnosis is only made after biopsy since clinical signs and symptoms and radiological findings are not pathognomonic. Symptomatology mainly derives from tumour encroachment and infiltration of adjacent intracranial structures. Surgery is the treatment of choice, while radiotherapy has an adjunctive role. Chemotherapy is not effective. Partial tumour excision to alleviate symptoms is an acceptable surgical technique since diagnosis is usually late, but treatment can be repeated when recurrence occurs. During the last year, two cases of chondrosarcoma of the skull base were treated in our institution. Both patients were female, aged 62 and 73, respectively. Computerized Tomography and Magnetic Resonance Imaging were inconclusive and diagnosis was established after biopsy. Treatment for both cases was surgical, with partial excision due to intracranial involvement of the internal carotid artery. In one case, a temporal approach was used, whereas the other patient was operated on via a naso-orbital approach. One patient received postoperative radiotherapy. The postoperative course was uneventful in both patients and marked clinical improvement was noted 18 months and 1 year after surgery. We support the view that partial resection of chondrosarcomas of the base of the skull to alleviate symptoms is an acceptable surgical treatment.