• "fried egg" appearance
    • Artifactual clearing of the cytoplasm
  • " Chicken wire" vascular pattern
    • Poor fibrillary matrix intersected by delicate, branching vessels

Uniform cell population with round nuclei and perinuclear halos + delicate blood vessels

  • Soft, gelatinous masses
  • Extend from the white to gray matter
    • Obliterating the gray–white junction
  • Cystic degeneration and calcification are common
  • Low incidence of TP53
  • Intense GFAP immunoreactivity

Oligodendrogliomas —> diffusely infiltrate the cerebral cortex forming characteristic secondary structures such as perineuronal satellitosis, perivascular accumulations, and subpial infiltration.

The diagnosis of oligodendrogliomas is primarily based on observations on hematoxylin and eosin (H&E) stained sections and the absence of reactivity for markers associated with astroglial differentiation.

  • 60–90% —> losses on chromosomes 1p & 19q
    • Translocation t(1;19)(q10;p10)
  • So if 1p/19q co-deletions in a glioma is detected it is associated with an oligodendroglial phenotype
  • In pediatric population rarely these deletion seen…

Chromosome 1p/19q codeletions have been associated with longer survival and a better response to therapy(PCP) in both low-grade and anapaestic oligodendrogliomas.

Other findings —> mutations of the TP53 gene and/or loss of heterozygosity (LOH) on chromosome 17p

Median Survival —> ~ 5year