Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.
Q: Abstract: Mucoceles of the sphenoid sinus are rare. Only occasional reports have appeared in the medical literature since they were first described by Berg in 1889. The sphenoid sinus lies deep within the skull at the crossroads of 13 sensitive structures. The presence of a sphenoid sinus mucocele may be accompanied by a wide variety of signs and symptoms depending upon which of these structures are involved. The majority of these lesions are initially misdiagnosed as malignancies leading to increased patient morbidity and possible mismanagement. We present two cases of sphenoid sinus mucoceles which presented with a variety of neurological signs and symptoms. The radiographic findings were felt to be consistent with skull base malignancies. The diagnosis was corrected only after surgical exploration of the sphenoid sinus revealed a mucocele.
A:
Case Report