Oligodendroglioma

Oligodendrogliomas, the third most common glial neoplasms, are diffusely infiltrating, well-differentiated, slowly growing tumors. They are round or oval and involve the cortex or subcortical white matter. They typically contain calcifications (80% of cases) and most commonly affect the frontal lobe.

on CT, they present as mixed attenuation cortically based lesions with nodular or clumped calcifications. Cystic degeneration is seen in about 20% of cases. Bone windows may reveal expansion, remodeling or erosion of bone. There is variable enhancement and little to no surrounding edema.

The lesions are heterogeneously hypointense to isointense to gray matter on T1-weighted images and demonstrate cortical expansion. T2-weighted images reveal minimal associated edema surrounding a heterogeneously hyperintense mass. Low signal areas correspond to calcium (common) or blood (seen in anaplastic types). No diffusion restriction is typical for these lesions. Oligodendrogliomas typically demonstrate variable and heterogeneous enhancement.

References

Koeller KK, Rushing EJ. From the archives of the AFIP: Oligodendroglioma and its variants: radiologic-pathologic correlation. Radiographics. 2005 Nov-Dec;25(6):1669-88.