Cavernous sinus-invading cranial base metastasis from renal clear cell carcinoma: a case report

Introduction and importance: Skull base metastasis from clear cell renal carcinoma (ccRCC) is exceptionally rare and associated with a poor prognosis. Presentation of the case: We report the case of a 60-year-old man with a skull base metastatic tumor and a prior history of ccRCC. He presented with an unexplained headache accompanied by right facial numbness, right-sided hearing loss, and tinnitus. He later developed recurrent epistaxis, prompting cranial computed tomography and magnetic resonance imaging, which revealed a mass lesion in the sphenoid sinus. Based on imaging findings, a skull base tumor was suspected, and surgical resection was performed. Clinical discussion: In patients with intracranial lesions on imaging and a known history of malignancy, intracranial metastases should be strongly considered. Early biopsy and timely surgical intervention are critical for diagnosis and management. Conclusion: Endoscopic resection via the middle cranial fossa approach can safely achieve complete removal of metastatic skull base tumors involving the cavernous sinus.