title: Intradiploic arachnoid cyst identified by diffusion-weighted magnetic resonance imaging--case report.
abstract: A 72-year-old woman presented with an intradiploic arachnoid cyst in the occipital intradiploic space which was found incidentally by magnetic resonance (MR) imaging. Computed tomography revealed a widened diploic space and thinning of the inner and outer tables of the occipital bone. The cyst appeared as isointense to the cerebrospinal fluid on both T1- and T2-weighted images. The differential diagnosis of intradiploic epidermoid cyst could be excluded because the lesion was low intensity on diffusion-weighted MR images. Arachnoid cyst is a benign lesion, so exploratory surgery should be avoided unless the cyst is symptomatic. Diffusion-weighted MR imaging is an effective modality to distinguish diploic epidermoid cysts from arachnoid cysts.
authors.affiliation: Department of Neurosurgery, Shobara Red Cross Hospital, Hiroshima, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Taizo
authors.initials: T
authors.lastname: Hirohata
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sumida
authors.forename: Kazunori
authors.initials: K
authors.lastname: Arita
authors.forename: Kaoru
authors.initials: K
authors.lastname: Kurisu
mesh_terms: D000368:Aged; D016080:Arachnoid Cysts / Q000175:diagnosis* / Q000601:surgery; D002555:Cerebrospinal Fluid; D003937:Diagnosis, Differential; D004814:Epidermal Cyst / Q000175:diagnosis; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D009777:Occipital Bone / Q000473:pathology