title: [Report of seven cases of clear-cell meningioma and a literature review].
abstract: OBJECTIVE
  Clear cell meningioma (CCM) is a rare variant of meningioma, which is important to distinguish because of its aggressive behaviour. Sixty-eight cases have been previously described in the literature. In this retrospective study, we report seven cases of CCM operated in our institution between 1994 and 2008.
  
  
  METHODS
  Seven CCM cases were retrieved from the files of our pathology department. Clinical and radiological data were reviewed. A standard histological study was realized and immunohistochemistry was performed with epithelial membrane antigen (EMA), cytokeratin KL1, progesterone receptors, Ki-67 (MIB-1), S100 protein.
  
  
  RESULTS
  Patients' age ranged from 2 to 70 years (median age: 36 years), with a female predominance (5/7 patients). Three patients belonged to the same family, probably affected by neurofibromatosis type 2. CCM occurred in various locations: medullary region (two), sphenoid wing (two), ponto-cerebellar angle (two), tentorium (one). The tumour could be fully resected in three cases. Follow-up ranged from 3 months to 15 years: recurrence occurred in four patients, three of whom eventually died from the disease.
  
  
  CONCLUSIONS
  In our series, the frequency of CCM (0,6% of all meningiomas operated on in our institution) and its histological aspects are almost identical to those observed of the literature. We discuss the predictive value of proliferation index (MIB-1) and the role of patient status and quality of surgical resection in the evolution.
  
  
  CONCLUSIONS
  Our study supports the fact that MCC course is less favourable than meningioma WHO grade I, even in the absence of anaplastic area, high mitotic activity, or necrosis. In this series, MIB-1 index was of no interest identifying patients with or without recurrence.
authors.affiliation: Service d'anatomie et cytologie pathologiques, hôpital Bretonneau, CHRU de Tours, 2, boulevard Tonnellé, 37044 Tours cedex 9, France. rousselot.cecilia@gmail.com
authors.forename: Cécilia
authors.initials: C
authors.lastname: Rousselot
authors.forename: Patrick
authors.initials: P
authors.lastname: Francois
authors.forename: Michel
authors.initials: M
authors.lastname: Jan
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Bergemer
mesh_terms: D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000175:diagnosis; D014408:Biomarkers, Tumor / Q000032:analysis*; D002675:Child, Preschool; D003951:Diagnostic Errors; D004806:Ependymoma / Q000175:diagnosis; D005260:Female; D006801:Humans; D007633:Keratins / Q000032:analysis; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008577:Meningeal Neoplasms / Q000737:chemistry / Q000175:diagnosis / Q000235:genetics / Q000473:pathology*; D008579:Meningioma / Q000737:chemistry / Q000175:diagnosis / Q000235:genetics / Q000473:pathology*; D008875:Middle Aged; D018396:Mucin-1 / Q000032:analysis; D009363:Neoplasm Proteins / Q000032:analysis*; D016518:Neurofibromatosis 2 / Q000175:diagnosis / Q000235:genetics / Q000473:pathology; D011980:Receptors, Progesterone / Q000032:analysis; D012189:Retrospective Studies; D009418:S100 Proteins / Q000032:analysis; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D018396:Mucin-1; D009363:Neoplasm Proteins; D011980:Receptors, Progesterone; D009418:S100 Proteins; D007633:Keratins