title: Clear cell meningiomas: three case reports with genetic characterization and review of the literature.
abstract: BACKGROUND
  Intracranial clear cell meningioma is very rare. We present 3 cases of intracranial clear cell meningiomas genetically characterized by comparative genomic hybridization with a review of the literature.
  
  
  METHODS
  Patient 1 is a 38-year-old woman with a petroclival tumor. Patient 2 is a 60-year-old man with a tumor at the foramen magnum. Patient 3 is a 60-year-old man with a tumor at the posterior clinoid process. Gross total resection was performed in patients 1 and 2. Patient 1 has been free from recurrence for 10 years. Patient 2 had a tumor recurrence at 14 months after the operation. After partial resection, conventional radiotherapy was given, and there was no tumor regrowth at 2 years after radiotherapy. Subtotal resection was performed in patient 3, and no regrowth was detected for 3 months. Histologically, all tumors were composed of cells with clear cytoplasm reactive for periodic acid-Schiff and diagnosed as clear cell meningioma. The MIB-1 and p53 staining indexes were 1.8, 1.7, and 5.6 and 1.1, 1.0, and 5.5, respectively. Comparative genomic hybridization revealed no chromosomal number aberrations in patient 1, numerous losses and gains including loss of chromosome 1 in patient 2, and loss of only 22q in patient 3. Because staining indexes of MIB-1 and p53 were equivalent in 2 patient (patients 1 and 2) with a long follow-up period, the contrary clinical courses are likely associated with genetic characteristics.
  
  
  CONCLUSIONS
  To the best of our knowledge, this is the first report that suggests association between tumor behavior and genetic characteristics in clear cell meningiomas.
authors.affiliation: Department of Neurosurgery, Keio University School of Medicine, Tokyo, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Ohba
authors.forename: Hikaru
authors.initials: H
authors.lastname: Sasaki
authors.forename: Tokuhiro
authors.initials: T
authors.lastname: Kimura
authors.forename: Eiji
authors.initials: E
authors.lastname: Ikeda
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kawase
mesh_terms: D000328:Adult; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000235:genetics* / Q000473:pathology* / Q000628:therapy; D008579:Meningioma / Q000235:genetics* / Q000473:pathology* / Q000628:therapy; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000235:genetics* / Q000473:pathology* / Q000532:radiotherapy; D019292:Skull Base Neoplasms / Q000235:genetics* / Q000473:pathology* / Q000628:therapy