BACKGROUND: Intradural 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 DESCRIPTION: We 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. CONCLUSION: The 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.
BACKGROUND: Intradural 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 DESCRIPTION: We 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. CONCLUSION: The 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.