RESUMEN
We report an uncommon case of a 45-year-old woman who presented with spontaneous rhinorrhea. A computed tomography (CT) scan of the head revealed an abnormally large sphenoid sinus associated with a parasellar bony defect (Sternberg's canal) through which magnetic resonance imaging could detect an encephalocele of the right temporal lobe. An endoscope-assisted trans-sphenoidal approach was performed and, with the aid of image guided surgery, reduction of the encephalocele was obtained and followed by surgical repair of the dural and bony defects. The postoperative course was uneventful and the cerebrospinal fluid fistula was closed as confirmed by the postoperative CT scan and by the absence of rhinorrhea. After three years of monitoring the patient remained asymptomatic.