title: Sclerosing Meningioma : Radiological and Clinical Characteristics of 21 Cases.
abstract: OBJECTIVE
  A rare subtype of meningioma, sclerosing meningioma is not included in the current World Health Organization classification of meningiomas and is classified into the category of other morphological variation subtypes. Sclerosing meningioma is often misdiagnosed to other non-benign meningioma or malignant neoplasm, so it is important to diagnose sclerosing type correctly. We analyzed the radiological and clinical characteristics of a series of sclerosing meningiomas.
  
  
  METHODS
  Twenty-one patients who underwent surgery in one institute with a histopathologically proven sclerosing meningioma were included from 2006 to 2014. Eighteen tumors were diagnosed as a pure sclerosing-type meningioma, and 3 as mixed type. Magnetic resonance image was taken for all patients including contrast enhancement image. Computed tomography (CT) scan was taken for 16 patients. One neuroradiologist and 1 neurosurgeon reviewed all images retrospectively.
  
  
  RESULTS
  In the all 16 patients with preoperative CT images, higher attenuation was observed in the meningioma than in the brain parenchyma, and calcification was observed in 11 (69%). In 15 of the 21 patients (71%), a distinctive very low signal intensity appeared as a dark color in T2-weighted images. Nine of these 15 tumors (60%) exhibited heterogeneous enhancement, and 6 (40%) exhibited homogeneous enhancement that was unlike the homogeneous enhancing pattern shown by conventional meningiomas. Ten patients had a clear tumor margin without peritumoral edema.
  
  
  CONCLUSIONS
  Although these peculiar radiological characteristics are not unique to sclerosing meningioma, we believe that they are distinctive features that may be helpful for distinguishing sclerosing meningioma from other subtypes.
authors.affiliation: Department of Neurosurgery, Seoul National University Hospital, Seoul, Korea.
authors.forename: Ho
authors.initials: H
authors.lastname: Kang
authors.affiliation: Department of Neurosurgery, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jin Wook
authors.initials: JW
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Seoul National University Hospital, Seoul, Korea.
authors.forename: Young-Bem
authors.initials: YB
authors.lastname: Se
authors.affiliation: Department of Neurosurgery, Seoul National University Hospital, Seoul, Korea.
authors.forename: Yun-Sik
authors.initials: YS
authors.lastname: Dho
authors.affiliation: Department of Radiology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Seung Hong
authors.initials: SH
authors.lastname: Choi
authors.affiliation: Department of Pathology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Sung-Hye
authors.initials: SH
authors.lastname: Park
keywords: Magnetic resonance imaging; Meningioma