title: Pleomorphic xanthoastrocytoma: a comparative pathological study between conventional and anaplastic types.
abstract: OBJECTIVE
  To facilitate the understanding and correct diagnosis of the anaplastic variant of pleomorphic xanthoastrocytoma (PXA).
  
  
  RESULTS
  Twelve cases of PXA were divided into six conventional and six anaplastic types. Three anaplastic PXAs developed in recurrent tumours and three occurred as the primary tumour. Anaplastic PXAs were microscopically characterized by monotonous proliferation of atypical cells, increased mitotic activity, necrosis and microvascular proliferation. Characteristic features of conventional PXA are also variously included in all anaplastic PXAs. No remarkable differences were detected in the immunohistochemical profiles including the neuronal phenotype between the conventional and anaplastic types. Ki67 labelling indices of the anaplastic type were significantly higher than those of the conventional type, whereas p53 showed no difference. Immunohistochemical and fluorescence in situ hybridization analyses on epidermal growth factor receptor did not demonstrate overexpression or gene amplification.
  
  
  CONCLUSIONS
  The anaplastic PXA, which occurs de novo or through recurrence, should be distinguished from glioblastoma by identifying the salient microscopic features of conventional PXA even in the anaplastic areas; and by demonstrating the expression of neuronal markers, in that the former is expected to have longer survival.
authors.affiliation: Department of Pathology, Saitama Medical School, Saitama, Japan. thirose@saitama-med.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Hirose
authors.forename: K
authors.initials: K
authors.lastname: Ishizawa
authors.forename: K
authors.initials: K
authors.lastname: Sugiyama
authors.forename: T
authors.initials: T
authors.lastname: Kageji
authors.forename: K
authors.initials: K
authors.lastname: Ueki
authors.forename: S
authors.initials: S
authors.lastname: Kannuki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001254:Astrocytoma / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology*; D002454:Cell Differentiation; D049109:Cell Proliferation; D002648:Child; D003937:Diagnosis, Differential; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D005909:Glioblastoma / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D009336:Necrosis / Q000473:pathology; D009474:Neurons / Q000473:pathology; D010641:Phenotype; D011379:Prognosis
chemical_list: D066246:ErbB Receptors