title: Pathological spectrum in recurrences of glioblastoma multiforme.
abstract: BACKGROUND
  Glioblastoma (GBM) is the most frequent primary malignant brain tumour. Despite advances in treatment its prognosis remains poor. Histological features of GBM are well known. On the contrary histological description of recurrences is still not available. The aim of this study was to describe the morphological, immunohistochemical and molecular features of recurrent GBMs.
  
  
  METHODS
  25 recurrent GBMs, diagnosed after 2005, were collected. All patients had undergone an adjuvant treatment regimen (temozolomide and/or radiotherapy). All cases were immunostained using anti-GFAP, Olig2 and Nogo-A antisera. MGMT and IDH1 status was reassessed. Features of the recurrences were compared with those of primary GBMs, time of recurrence and survival.
  
  
  RESULTS
  Recurrences were divided morphologically into three groups: 1) recurrences displaying the same features of primary GBM, were highly cellular, had the fastest progression and the worst prognosis; 2) recurrences changing dramatically morphological appearance, had a slightly longer survival, 3) poorly cellular recurrences, with sparse neoplastic cells intermingled with reactive and necrotic tissue, displayed the slowest progression and longer survival. MGMT and IDH1 status remained unchanged between primary tumours and recurrences.
  
  
  CONCLUSIONS
  GBM histological subtypes display different reactions to adjuvant treatments, offering a possible role in predicting different recurrence and survival time.
authors.forename: G
authors.initials: G
authors.lastname: Marucci
authors.forename: P V
authors.initials: PV
authors.lastname: Fabbri
authors.forename: L
authors.initials: L
authors.lastname: Morandi
authors.forename: D
authors.initials: D
authors.lastname: De Biase
authors.forename: E
authors.initials: E
authors.lastname: Di Oto
authors.forename: G
authors.initials: G
authors.lastname: Tallini
authors.forename: C
authors.initials: C
authors.lastname: Sturiale
authors.forename: E
authors.initials: E
authors.lastname: Franceschi
authors.forename: G P
authors.initials: GP
authors.lastname: Frezza
authors.forename: M P
authors.initials: MP
authors.lastname: Foschini
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D001932:Brain Neoplasms / Q000737:chemistry / Q000235:genetics / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D019175:DNA Methylation; D004252:DNA Mutational Analysis; D018450:Disease Progression; D005260:Female; D005909:Glioblastoma / Q000737:chemistry / Q000235:genetics / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009364:Neoplasm Recurrence, Local; D011237:Predictive Value of Tests; D013997:Time Factors
chemical_list: D014408:Biomarkers, Tumor