Chordomas and chondrosarcomas of the skull base

Abstract

Chordomas and chondrosarcomas are rare tumours that occur at the skull base. Chordomas have a benign appearing histology but behave malignantly with a high tendency to invade locally, recur, demonstrate tumour progression by accumulating genetic mutations, metastasize, and surgically implant. Aggressive treatment is necessary and radical resection including of the invaded bone followed by adjuvant high-dose radiation therapy offers the best chance for long-term disease-free survival. This requires initiating treatment at the onset, since once the tumour recurs the outcome is poor. Multiple surgical approaches may need to be employed to achieve the sought-after radical resection in a given patient. Utilizing all of the advances in operative techniques including microscopic and endoscopic techniques, intraoperative imaging, and neuronavigation facilitates this goal. Particle-based radiation has a proven record in a large experience as an adjunct to radical surgical resection. Chondrosarcomas are rarer and carry a better prognosis. Complete surgical removal has excellent recurrence-free survival rates. Radiation therapy has also showed high control rates but may not be necessary given their benign course. Immunohistochemical analysis is essential for ensuring the proper diagnosis.