title: Intraoperative cytologic diagnosis of chordoid meningioma. A case report.
abstract: BACKGROUND
  Chordoid meningioma is an uncommon supratentorial tumor in which a cordonal pattern on a mucofibrillar background covers areas of classic meningioma with a diffuse, meningeal, immunohistochemically reactive pattern. Its cytology has not been described before.
  
  
  METHODS
  A 45-year-old woman with headaches and a poorly defined, nondiplopic vision alteration underwent magnetic resonance imaging, which showed a tumor in the upper part of the left orbital cavity. An intraoperative squash smear showed closely knit, pseudosyncytial plates composed of medium-sized cells with homogeneous nuclei and nuclear pseudoinclusions. There were some physaliferouslike, loose cells without cytoplasmic vacuolation and a fairly abundant, metachromatic, pink to light purple background that was absent inside the plates. A diagnosis of meningioma with a possible chordoid pattern was made. No frozen intraoperative section was prepared. Histology showed 90% chordoid meningioma merging with areas of classic meningothelial meningioma and overall positivity for epithelial membrane antigen and vimentin. S-100 was negative.
  
  
  CONCLUSIONS
  A reliable intraoperative cytologic diagnosis of chordoid meningioma can be made because the morphology is highly characteristic. Close cellular association and the cells' nuclear traits are expected in a meningioma. The metachromatic background can cause a false diagnosis of chordoma. However, there are some clear differences in the cells and their relation to the mucofibrillar matrix that make the diagnosis definitive.
authors.affiliation: Department of Pathology, Hospital General Gregorio Marañón, Calle Dr. Esquerdo, 45, 28007 Madrid, Spain. emilio.salinero@madrid.org
authors.forename: Emilio
authors.initials: E
authors.lastname: Salinero
authors.forename: Luis
authors.initials: L
authors.lastname: Beltran
authors.forename: Julio R
authors.initials: JR
authors.lastname: Costa
mesh_terms: D001399:Azure Stains; D014408:Biomarkers, Tumor / Q000378:metabolism; D001706:Biopsy; D002467:Cell Nucleus / Q000473:pathology; D002817:Chordoma / Q000473:pathology; D003593:Cytoplasm / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007432:Intraoperative Period; D008577:Meningeal Neoplasms / Q000145:classification / Q000473:pathology* / Q000601:surgery; D008579:Meningioma / Q000145:classification / Q000473:pathology* / Q000601:surgery; D008751:Methylene Blue; D008875:Middle Aged; D018396:Mucin-1 / Q000378:metabolism; D009918:Orbital Neoplasms / Q000145:classification / Q000473:pathology* / Q000601:surgery; D015203:Reproducibility of Results; D014746:Vimentin / Q000378:metabolism; D014966:Xanthenes
chemical_list: D001399:Azure Stains; D014408:Biomarkers, Tumor; C067461:Diff Quik; D018396:Mucin-1; D014746:Vimentin; D014966:Xanthenes; D008751:Methylene Blue