Histological study on local invasiveness of clival chordoma. Case report of autopsy

Background. It is well known that clival chordomas invade bony structures; however, their invasiveness. of other structures has rarely been reported. We report an autopsy case of clival chordoma in a 61-year-old woman, who underwent surgery 6 times for a period of 8 years, with special reference to its local invasiveness. Method and Findings. The histological studies showed that the tumour grew in the loose connective tissue in multilayers or multilobular fashion, invading the submucous layer in addition to the bone; however, it did not invade other soft tissue, particularly vital neurovascular structures or the dura itself, even in the advanced stage. Interpretation. The dura may serve as a strong barrier against tumour invasion into the intradural space, which emphasises the importance of not injuring the dura, when the tumour is removed extradurally. For radical removal of clival chordoma, it will be necessary to remove the tumour extensively including normal bone and soft tissues surrounding the tumour, especially the mucous membrane, because the normal mucous membrane is surgically difficult to preserve by dissecting it from the invaded submucous layer.