title: Rhabdoid meningioma: clinical features and MR imaging findings in 15 patients.
abstract: OBJECTIVE
  Rhabdoid meningioma (RM) is a recently described variant of malignant meningioma, with radiologic features currently not well characterized in the medical literature. The purpose of this study was to describe and characterize clinical features and imaging findings associated with RM.
  
  
  METHODS
  CT (n = 8) and MR (n = 15) images of 15 patients (4 men and 11 women; mean age, 52 years; range, 22-75 years) with 16 pathologically proved RMs along with associated clinical records were retrospectively reviewed. All of the patients underwent surgical resection and had additional radiation therapy except for 1 patient. After surgery, the patients had follow-up brain MR imaging to evaluate for tumor recurrence.
  
  
  RESULTS
  Nine lesions (56%) were located in the cerebral convexity, and 4 lesions (25%) were located in the parasagittal areas. The tumors were isointense (n = 15) to gray matter on T1-weighted images, whereas they were hyperintense (n = 14) on T2-weighted images. On gadolinium-enhanced T1-weighted images, homogeneous enhancement was seen in 10 lesions, and heterogeneous enhancement was seen in 6 lesions that had cysts. Cystic components were noted in 6 lesions (38%). Severe peritumoral edema was seen in 12 lesions (75%). Nine lesions (56%) had hyperostosis, and 5 of them also had bone destruction. Among the 8 cases with initial CT scans, only 1 had amorphous calcifications (13%). There was only 1 recurrence of RM found during the follow-up period after surgical resection.
  
  
  CONCLUSIONS
  RMs tend to have prominent peritumoral edema, cystic components, and bone involvement.
authors.affiliation: Department of Radiology and Centers for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: E Y
authors.initials: EY
authors.lastname: Kim
authors.forename: Y C
authors.initials: YC
authors.lastname: Weon
authors.forename: S T
authors.initials: ST
authors.lastname: Kim
authors.forename: H-J
authors.initials: HJ
authors.lastname: Kim
authors.forename: H S
authors.initials: HS
authors.lastname: Byun
authors.forename: J-I
authors.initials: JI
authors.lastname: Lee
authors.forename: J H
authors.initials: JH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D003560:Cysts / Q000175:diagnosis; D004487:Edema / Q000139:chemically induced / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015576:Hyperostosis / Q000175:diagnosis / Q000209:etiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008577:Meningeal Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology* / Q000601:surgery; D008579:Meningioma / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology* / Q000601:surgery; D008875:Middle Aged; D019635:Neurosurgical Procedures; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed