Intradural cranial chordoma

BackgroundIntradural chordomas are rare and have been considered benign owing to the feasibility of complete resection and the display of lesser aggressive biologic behavior than typical chordomas.Case DescriptionWe herein reported 2 cases of intradural cranial chordoma with aggressive biologic behavior. A tumor (anti–Ki-67 monoclonal antibody [MIB-1], 13.9%) in a 59-year-old woman was strongly adherent to the brainstem and involved the basilar artery and its branches. After subtotal removal, the remnant tumor was treated with stereotactic radiotherapy. A tumor (MIB-1, 6.2%) in a 75-year-old woman repeatedly recurred even after initial gross total removal. The recurrent chordomas were treated with γ-knife radiosurgery.ConclusionThe cases presented in this study indicate that intradural chordomas can also be aggressive such as typical chordomas. Long-term follow-ups with a large number of patients with this condition are essential for elucidating the prognosis of intradural chordomas.