title: Pilocytic astrocytomas in children: prognostic factors--a retrospective study of 80 cases.
abstract: OBJECTIVE
  Pilocytic astrocytomas (PA) are Grade I brain tumors characterized by an excellent prognosis. In some cases, however, the patient has a bad outcome. The aim of our study was to search for the clinicopathological factors underlying the prognosis for patients with this disease.
  
  
  METHODS
  We reviewed the clinical, neuroradiological, and histopathological features of 80 PAs (33 cerebellar, 18 optochiasmatic, 16 brainstem, 7 spinal cord, 3 thalamic, 2 optic nerve, and 1 hemispheric) in pediatric patients.
  
  
  RESULTS
  Pathological examination revealed 58 classic PAs and 20 pilomyxoid astrocytomas, which are a histological variant of PAs. Two cases remained unclassified. The mean overall follow-up period was 58 months, the 5-year progression-free survival rate was 75%, and the 5-year survival rates were 100 and 92% after total and partial removal. Univariate statistical analysis revealed that partial resection, optochiasmatic PA localization, and pilomyxoid variant were associated with a worse prognosis, but the latter two parameters were too closely related to the extent of resection to be independent prognostic factors in multivariate analysis. Among the patients who underwent partial surgical removal, only invasion of the surrounding structures was related to prognosis.
  
  
  CONCLUSIONS
  PAs are benign tumors, but some clinicopathological factors, such as partial resection, optochiasmatic location, invasion of surrounding structures, and the pilomyxoid variant, have a worse prognosis.
authors.affiliation: Service d'Anatomie Pathologique et de Neuropathologie, Hôpital de la Timone, Marseille, France.
authors.forename: Carla
authors.initials: C
authors.lastname: Fernandez
authors.forename: Dominique
authors.initials: D
authors.lastname: Figarella-Branger
authors.forename: Nadine
authors.initials: N
authors.lastname: Girard
authors.forename: Corinne
authors.initials: C
authors.lastname: Bouvier-Labit
authors.forename: Joanny
authors.initials: J
authors.lastname: Gouvernet
authors.forename: Armando
authors.initials: A
authors.lastname: Paz Paredes
authors.forename: Gabriel
authors.initials: G
authors.lastname: Lena
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001254:Astrocytoma / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D001932:Brain Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D019574:Optic Nerve Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D017063:Outcome Assessment, Health Care; D011379:Prognosis; D012189:Retrospective Studies; D013120:Spinal Cord Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D015996:Survival Rate; D014057:Tomography, X-Ray Computed