Endoscopic endonasal treatment of a large clival giant cell tumor invading the cavernous sinus and temporal lobe.

Giant cell tumors (GCTs) are extremely rare lesions, representing less than 5% of all bone tumors. They primarily occur in the long bones. However, a small percentage of these tumors occur in the pelvis, spine, or skull bones. These lesions are usually benign as well as locally aggressive and require complete removal. Nowadays, GCT and other skull base lesions can be treated using the extended endoscopic endonasal approach. We present a case report of a GCT located in the skull base, originating from the clivus and sphenoid bone, invading through the cavernous sinus, and treated using the fully endoscopic endonasal approach.