title: Dual use of E-cadherin and D2-40 immunostaining in unusual meningioma subtypes.
abstract: OBJECTIVE
  Meningiomas usually can be readily diagnosed on H&E alone, although occasionally immunohistochemistry (IHC) confirmation is desirable. Studies exploring the diagnostic utility of either podoplanin (D2-40) or E-cadherin IHC in meningiomas have conflicted, and no studies exist in which the two IHCs have been used in combination for diagnosis.
  
  
  METHODS
  E-cadherin and D2-40 IHC was performed on 77 meningiomas (31 ordinary; eight microcystic; four rare myxoid; six metaplastic; six invasive of orbit, muscle, and/or soft tissue; two metastatic; six brain-invasive World Health Organization [WHO] grade II, nine non-brain-invasive WHO grade II; and five anaplastic WHO grade III), with semi-quantitative scoring on a three-tier scale (0, focal [1+], strong/diffuse [2+]).
  
  
  RESULTS
  All meningiomas were either E-cadherin or D2-40 IHC+, with 69 of 77 showing dual immunostaining, most at the 2+ level. No downregulation of E-cadherin IHC was found in invasive or high-grade meningiomas.
  
  
  CONCLUSIONS
  Dual E-cadherin/D2-40 IHC can supplement diagnosis of meningioma.
authors.affiliation: From the Department of Pathology, University of Colorado Health Sciences Center, Aurora.
authors.forename: E Kelly S
authors.initials: EK
authors.lastname: Mrachek
authors.affiliation: From the Department of Pathology, University of Colorado Health Sciences Center, Aurora.
authors.forename: David
authors.initials: D
authors.lastname: Davis
authors.affiliation: From the Department of Pathology, University of Colorado Health Sciences Center, Aurora. bk.demasters@ucdenver.edu.
authors.forename: B K
authors.initials: BK
authors.lastname: Kleinschmidt-DeMasters
mesh_terms: D058846:Antibodies, Monoclonal, Murine-Derived / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis; D015820:Cadherins / Q000032:analysis / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D008577:Meningeal Neoplasms / Q000175:diagnosis*; D008579:Meningioma / Q000175:diagnosis*; D012189:Retrospective Studies
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D014408:Biomarkers, Tumor; D015820:Cadherins; C500987:monoclonal antibody D2-40
keywords: Anaplastic meningioma; Immunohistochemistry; Invasive meningioma; Microcystic meningioma; Myxoid meningioma