Treatment of a sphenoid sinus mucocele using an endoscope combined with a navigating system: a case report.

A sphenoid sinus mucocele extending into the middle cranial fossa and the pterygomaxillary fissure was decompressed using an endoscope in combination with a navigation system. A 59-year-old woman was admitted with a 3 month history of retro-ocular pain and right sided exophthalmos. To evaluate the cystic lesion, a fibreoptic endoscope was inserted into the cyst through an erosive defect in the temporal bone. The histopathological appearance of cyst wall tissue confirmed the diagnosis of mucocele. After 4 months, the mucocele had refilled and the exophthalmos had recurred. At reoperation, the cyst was fenestrated using a rigid endoscope combined with a navigation system inserted via a sublabial transmaxillary approach. The proper site of cyst fenestration was precisely determined using the navigation system, permitting complete evacuation of this large lesion with minimal invasiveness.