[Diagnosis and surgical strategy in 3 cases of benign and unusual tumors of the occipito-cervical skeleton].

The authors report three cases of benign tumours of the occipito-cervical skeleton, remarkable for their rarity and especially by their unusual, even exceptional anatomic site: an osteoid osteoma, a pre-medullary chondroma and an extra-dural exostosis developing within a hereditary multiple disease. This presentation which allows to recall a few epidemiological and diagnostic problems is essentially focused on operative strategy and particularly on the choice of the best way to cope with surgical difficulties to be met. The osteoid osteoma whose diagnosis is difficult raises two surgical problems: the relation with the vertebral artery and the preservation of the atlanto-occipital joint. An approach through limited occipital craniotomy has allowed a perfect control of the vertebral artery and a complete removal without joint damage. Pre-medullary chondroma: a complete removal has been performed through the anterior way as described in rare observations of the literature. Post operatively, the patient had a complete neuro-orthopedic recovery. The antero-lateral exostosis has been removed through the posterior way by first resecting the basis of implantation, which has allowed the mobilization of the lesion without cord damage. Results have been good in the three cases both from neurological and orthopedic points of view.