title: Secretory meningioma with KLF4 K409Q mutation in collision with glioma.
abstract: OBJECTIVE
  The simultaneous occurrence of two primary intracranial tumors is a rare event, especially if unrelated to radiotherapy or genetic disorders. We present two patients, both with two primary intracranial tumors simultaneously present at adjacent sites, in order to explore a possible mechanism of synchronous tumor formation.
  
  
  METHODS
  We performed a molecular analysis of the K409Q mutation of the KLF4 gene, in addition to conventional immunohistochemistry.
  
  
  RESULTS
  Preoperative gadolinium-enhanced magnetic resonance imaging revealed a necrotic mass with an irregular ring-like enhancement adjacent to a frontal meningioma in patient 1, and an infiltrative non-enhancing glial tumor with no evidence of another tumor in patient 2. Postoperative histological examination revealed the presence of two distinct tumors in both cases: secretory meningioma and glioblastoma in patient 1 and secretory meningioma and anaplastic astrocytoma in patient 2. Secretory meningiomas both showed the KLF4 K409Q mutation, while none of the glial tumors had it.
  
  
  CONCLUSIONS
  To our knowledge, these are the first two cases reported of the simultaneous occurrence of secretory meningiomas with mutation of KLF4 in collision with a glioblastoma and an anaplastic astrocytoma, respectively. These collision tumors presumably have different molecular origins.
authors.forename: Juan
authors.initials: J
authors.lastname: Ruiz
authors.forename: Elena
authors.initials: E
authors.lastname: Capilla
authors.forename: Juan F
authors.initials: JF
authors.lastname: Díaz
authors.forename: Juan A
authors.initials: JA
authors.lastname: Ruiz
authors.forename: Jesus
authors.initials: J
authors.lastname: Andrade
authors.forename: Teresa
authors.initials: T
authors.lastname: Hernández
authors.forename: Manuela
authors.initials: M
authors.lastname: Mollejo
authors.forename: Bárbara
authors.initials: B
authors.lastname: Meléndez
mesh_terms: D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D005260:Female; D005909:Glioblastoma / Q000175:diagnosis / Q000235:genetics*; D005910:Glioma / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000235:genetics*; D008577:Meningeal Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D008579:Meningioma / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D009154:Mutation / Q000235:genetics*; D055815:Young Adult
chemical_list: C000715467:KLF4 protein, human; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors