ENDOSCOPIC MANAGEMENT OF A GIANT CHOLESTEROL CYST OF THE PETROUS APEX

Giant cholesterol cyst (GCC) of the petrous apex is a rare clinical en tity. This benign cystic lesion can cause neurologic deficits and vasc ular compromise by persistent growth and progressive bone destruction. Magnetic resonance imaging studies of GCC show the lesions to be hype rintense on T-1-weighted sequences with progressively lower signal int ensities on the first and second echoes of T-2-weighted sequences. The se findings are relatively specific for GCC, permitting a narrow diffe rential diagnosis. The goal of surgery is to provide adequate drainage with the creation of a permanent fistula. The classic approaches to t hese lesions are the posterior fossa craniotomy and the middle fossa e xtradural craniotomy. The translabyrinthine approach provides wide exp osure at the expense of cochlear and vestibular function. The transsph enoidal approach provides adequate drainage with hearing preservation and no craniotomy. The endoscopic, endonasal transsphenoidal approach to a 2.5 cm GCC of the petrous apex accomplished complete drainage wit h the creation of a fistula. Advances in endoscopic technique and inst rumentation facilitated the addition of the approach to the surgeon's armamentarium. In selected cases, this approach provides adequate surg ical exposure with minimal morbidity.