title: Ossified Intracranial Meningiomas: Description of the First Series of Cases and Review of the Literature.
abstract: BACKGROUND
  Metaplastic meningiomas are characterized by mesenchymal differentiation with formation of bone, cartilage, fat, or xanthomatous elements. However the presence of extensive areas of ossification is rare in meningiomas. In addition, intracranial location of ossified meningiomas is uncommon. Surgical management represents the optimal treatment for ossified meningiomas, but ossification may interfere with surgery and condition outcome.
  
  
  METHODS
  By reviewing patient records and contacting patients, families, and referring physicians, the following information was gathered: age, sex, tumor location, clinical presentation, preoperative and postoperative functional status, and surgical data. Each surgical specimen had been formalin-fixed, paraffin-embedded, and cut into parallel 4-μm-thick sections for histological evaluation.
  
  
  RESULTS
  Our literature search identified 8 cases, all of whom had undergone surgical treatment. Histopathological analysis revealed the presence of disorganized bone spicules with solitary oval osteocytic nuclei and lined by osteoblasts, with clear evidence of bone tissue in at least 50% of tumor tissue.
  
  
  CONCLUSIONS
  Here we present the largest series, to our knowledge, of surgically treated intracranial ossified meningiomas reported to date. The mechanism of ossification in these meningiomas remains unclear, and various hypotheses have been formulated. Complete lesion removal, or subtotal debulking in those cases characterized by tenacious adherences to vascular structures and/or critical areas, may represent the optimal treatment.
authors.affiliation: Neurosurgical Clinic, Department of Neuroscience, University of Messina School of Medicine, Messina, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Caffo
authors.affiliation: Neurosurgical Clinic, Department of Neuroscience, University of Messina School of Medicine, Messina, Italy. Electronic address: gcaruso@unime.it.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Caruso
authors.affiliation: Department of Human Pathology, University of Messina School of Medicine, Messina, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Barresi
authors.affiliation: Neurosurgical Clinic, Department of Neuroscience, University of Messina School of Medicine, Messina, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Tomasello
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000473:pathology* / Q000601:surgery*; D008579:Meningioma / Q000473:pathology* / Q000601:surgery*; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000473:pathology* / Q000601:surgery*; D016896:Treatment Outcome
keywords: Calcified meningiomas; Meningiomas; Metaplastic meningiomas; Ossified meningiomas; Osteoblastic meningiomas; Osteomatous meningiomas