RESUMO
We report the case of a 36 year-old man with relapsing undifferentiated nasopharyngeal carcinoma treated with a re-irradiation Cyberknife, who subsequently developed tension pneumocephalus due to a cerebrospinal fluid leakage located at the clivus. The fistula was caused by osteonecrosis of the skull base secondary to the tumor invasion and to the sequelae of the radiotherapy. An endoscopic endonasal technique was used in order to repair the defect, with a peduncolated nasoseptal flap harvested to perform the skull base reconstruction. In this paper, we discuss the importance of identifying this possible complication related to radiotherapy in the management of neoplasm along the skull base; moreover, the role of endoscopy in the diagnosis and treatment of skull base fistulas is also described and commented.