[Endoscopic Endonasal Surgery for Skull Base Chordomas and Chondrosarcomas : Basic to Advanced Cases].

Skull base chordomas and chondrosarcomas are rare bone tumors predominantly found in the petroclival areas and involve the cranial nerves, internal carotid arteries, and brain stem. Their clinical aggressiveness and high risk of recurrence necessitate multimodal treatments, including extensive surgical resection and high-dose radiotherapy. Surgery is commonly the first step in their treatment, and ABCD rules should be respected; anatomical preservation of the innocent nasal anatomy for potential repeated surgeries in case of recurrence, block-by-block resection, coverage of the intradural residual tumor to prevent surgical site dissemination and cerebrospinal fluid dissemination, and drilling of the marginal bone. Here, we present our surgical strategy for skull base chordomas and chondrosarcomas for radical surgical resection and extirpation of the tumor.