title: Intradiploic epidermoid cyst with focal internal enhancement.
abstract: We report a case of intradiploic epidermoid cyst with focal internal enhancement. The patient was a 55-year-old woman presenting with right temporal head protrusion and head heaviness. Skull radiography and computed tomography demonstrated an expansile mass in the right diploic space. On magnetic resonance imaging, the mass showed makedly high signal T2-weighted images (T2WI) and intermediate to low signal on T1WI. On contrast-enhanced T1WI, there was nodular internal enhancement, which corresponded to neovascularity on pathology, as well as rim-like enhancement. It should be noted that internal enhancement, an indicator of malignant transformation, may be seen even in a benign epidermoid cyst.
authors.affiliation: Department of Radiology, St. Marianna University Toyoko Hospital, Kosugi-cho, Nakahara-ku, Kawasaki 211-0063, Japan. nambu-a@gray.plala.or.jp
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nambu
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Imanishi
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Iwasaki
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Fujikawa
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Hayashi
authors.forename: Toshihito
authors.initials: T
authors.lastname: Shinagawa
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Araki
mesh_terms: D004814:Epidermal Cyst / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D010294:Parietal Bone; D013701:Temporal Bone