Aneurysmal Bone Cyst of the Skull Base in a 17-Year-Old Boy Who Was Referred with Unusual Presentation

Aneurismal Bone Cyst (ABC) is an osteolytic lesion"ncommonly observed in the first and second decades of"nlife more in females. They typically involve the long"nbones. Skull base involvement is rare. We describe"na 17-year-old boy with ABC of the skull base with"nforamen Jugular symptoms. Our case presented with a"nhistory of hoarseness for 2 years and facial asymmetry"nand left sided hearing loss from 5 months ago with no"nhistory of trauma or surgery. On physical examination,"nhe had left-sided sensorineural hearing loss with left"njugular foramen syndrome. The exam was otyherwise"nunremarkable. On MRI sequences an iso signal"nAbstracts"nIran J Radiol 2011, 8 (Supp.1) S61"nlobulated well defied mass containing few high signal"nareas in T1W and heterogeneous high signal (T2W"nand Flair) was noted arising from the jugular foramen"nextending to the inferior cerebello-pontine angle"nwhich showed severe enhancement containing low"nsignal areas. No fluid-fluid level or enhancing septa was"nnoted. On CT scan a lytic expansile mass was detected"non the left side of foramen magnum and clivus with"ninvolvement of petrous apex and the internal auditory"ncanal. According to MRI findings, glomus jugular,"nschwannomas and meningiomas, but based on CT"nscan and MRI findings giant cell tumor and based on"nthe patient;s age ABC were our differential diagnosis."nThe lesion was only resected (without radiotherapy)"nand histopathology confirmed an ABC. No recurrence"nwas observed after 6 months. Our case was interesting"nbecause of its rarity; not only the clinical jugular"nforamen syndrome but also the unusual radiological"npresentations such as severe enhancement, lack of"nfluid level and multi osseous involvement."nKeywords: Aneurysmal Bone Cyst, Foramen Jugular,"nPetros, Skull bBase, Clivus