Primary intradural pontocerebellar chordoma metastasizing in the subarachnoid spinal canal.

Chordomas that are entirely extraosseous and intradural are rare. Additionally subarachnoid spinal implantation from such a cranial, intradural chordoma has never been reported before. The authors present a case of a widespread primary intradural chordoma in the basal cisterns of a 48-year-old woman which shows seeding of neoplastic cells to the spinal leptomeninges. It is concluded that also in cases of intradural and intracranial chordomas a tumor staging should include the search for spinal subarachnoid metastases.