Multiple Surgical Treatments for Repeated Recurrence of Skull Base Mesenchymal Chondrosarcoma.

We report a case of a young male who received multiple surgical treatments for repeated recurrence of skull base mesenchymal chondrosarcoma (MC). When the patient was 18 years old, we subtotally removed the skull base MC and he was treated with stereotactic radiosurgery for remnant tumors in the left cavernous sinus. After 30 months, we removed residual tumors that had regrown partially, via combined endonasal endoscopic and orbitozygomatic approaches. Over the next 65 months, the patient refused radical resection, and received six salvage surgeries, two stereotactic radiotherapies, and five stereotactic radiosurgeries for repeated recurrence. At 95 months after initial surgery, the tumors had extended to the skull base and nasal cavities. As a result, the left eye had been blinded and right visual acuity was deteriorated. We performed left anterior-middle cranial base resection, removal of nasal and intradural tumors, high flow bypass, en-bloc resection of the left cavernous sinus and clivus, and reconstruction using an abdominal flap. Even though the main tumors were removed with safety margins, tumors around the right optic nerve were removed by piecemeal to preserve right eye function. Six months after the radical resection, tumors in the right orbital apex recurred because we had been unable to remove the tumor with adequate safety margins. Skull base MC has a high tendency to recur locally, so these tumors should be radically removed with safety margins as early as possible to prevent recurrence.