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Axial (FLAIR) of Oligodendroglioma
|Treatment||Surgery, Chemotherapy, Radiation|
Occurs equally in females and males; most commonly in the frontal lobes and in adults age 30-50
Oligodendrogliomas are more chemosensitive than other tumors (PCV and Temodar) and are more prone to hemorrhage than other gliomas. Controversy exists regarding the value of extent of resection of these tumors.
Genetically: very frequently have p53 mutations and EGF-receptor overexpression; commonly see loss of heterozygosity for chromosomes 1p and 19q. This chromosomal loss correlates with a better response to chemotherapy.
Composed of uniform cells that infiltrate gray matter but tend to produce a more abrupt edge in white matter; small amounts of calcification are typically found often at the edge of the tumor; An artifactual clearing of the cytoplasm is common in fixed paraffin embedded material giving the cells a fried egg appearance
CT: oligodendrogliomas are the most common intracranial tumor to calcify with 2/3rds showing moderate enhancement MRI: mixed hypo and isointense areas on T1 and hyperintense of on T2 sequences
As with most glial neoplasms, surgical resection is not curative, but is often employed for diagnostic and therapeutic benefit, particularly if there is significant mass effect or hemorrhage. Tumors that have a 1p/19q deletion have a significantly better response to treatment (historically procarbazine, CCNU, and Vincristine, but also seen with Temozolomide) than tumors without these chromosomal deletions. Radiotherapy may delay time to progression, but remains controversial for Grade II tumors.