[Chondrosarcoma of the skull base. Apropos of sphenotemporal localization and review of the literature].

The authors report a case of chondrosarcoma of the skull base with a myxoïd histology, developed from the right sphenotemporal junction. Twenty six months after enlarged tumour removal, there are no clinical or neuroradiological signs of recurrence. A review of the 180 published cases emphasizes the rarity of this tumour originating of the skull base synchondrosis and occurring in young patients. MRI forms the basis of the topographic work-up but does not formally distinguish it from chordoma. Diagnosis is confirmed by histology which establishes a prognostic scale. Immunohistochemistry eliminates chondroïd chordoma by demonstrating a mesenchymatous phenotype. Only enlarged tumour removal can prolong survival even though improvements have been made in high energy radiation therapy and radiosurgery. Cases of recurrence or rare metastasis are probably due to incomplete exeresis and in most cases linked to high grade histology tumours.