Chordomas and chondrosarcomas

Abstract

Primary bone tumors of the skull base are unusual pathologies, mostly chordoma and chondrosarcoma [44]. Their development sends us to the embryological period in which the axial skeleton is formed [21]. The notochord is the initial axial skeletal structure that is progressively involved by the mesodermal tissue and later on replaced by cartilaginous and bone tissues [21]. Remnants of the notochord may remain entrapped by bone [21, 29], particularly in the clivus and sacrum [28, 29, 56]. They are also encountered in the nucleus pulposus [56] or forming a rather distinct intradural clival mass that may be found incidentally at autopsy, namely the ecchordosis physalifora [23]. In addition, focal persistent rests of fetal cartilage may remain unchanged in the skull base during ossification [11, 44]. © 2008 Springer-Verlag.