title: Morphophenotype of medulloblastoma in children and adults. The size of nuclei.
abstract: OBJECTIVE
  Uniform cells with round, regular nuclei characterize the typical histologic aspect of medulloblastoma. Enlargement of nuclei distinguishes the large-cell medulloblastoma variant and is associated with a poor prognosis in pediatric medulloblastomas. The aim of the present study was to compare the size of nuclei between pediatric and adult medulloblastomas by a morphometric analysis.
  
  
  METHODS
  In 79 neurosurgical specimens of cerebellar medulloblastomas, the maximum nuclear diameter of the largest nuclei was measured. Measurements were performed with a digital-image analysis system. The measure of the maximum diameter was chosen in order to reduce the split cell error.
  
  
  RESULTS
  The difference between the mean values in children and adults was statistically significant (p = 0,001). The distribution of maximum values measured in each case had two distinct peaks in the two age groups, in 3.5% of adult cases and in more than 30% of pediatric cases the maximum nuclear size was superior to 12 microm.
  
  
  CONCLUSIONS
  The present results show that nuclei of tumor cells in pediatric medulloblastomas are larger than those in adult medulloblastomas and confirm that the phenotype of medulloblastoma is different in the two age groups. Distinct genetic events can, thus, underlie medulloblastoma in childhood and adult age, the prognostic role of genetic variables can differ by age.
authors.affiliation: Department of Neuroscience, University of Torino, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Dagostino
authors.forename: E
authors.initials: E
authors.lastname: Clara
authors.forename: A
authors.initials: A
authors.lastname: Chio
authors.forename: M T
authors.initials: MT
authors.lastname: Giordana
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002467:Cell Nucleus / Q000235:genetics / Q000648:ultrastructure*; D002528:Cerebellar Neoplasms / Q000235:genetics / Q000648:ultrastructure*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D008297:Male; D008527:Medulloblastoma / Q000235:genetics / Q000648:ultrastructure*; D008875:Middle Aged; D011379:Prognosis