Oligodendroglioma, WHO grade II

A mass lesion is noted on the right, in the posterior frontal lobe, somewhat peripherally located and expansile in nature. The lesion is hyperintense on T2-weighted scans, and fairly homogeneous in nature. There was no abnormal contrast enhancement (image not shown). In neoplastic disease, choline is increased and NAA decreased, relative to normal brain, a finding well illustrated by the spectra from within the lesion. Lactate (an inverted peak) is seen at about 1.4 ppm, with an additional lipid peak to the right. Higher-grade glial tumors tend to have lipid and lactate, as a result of necrosis. Lactate, which results from anaerobic metabolism, can also be seen in infarction. Active left hand movement (fMRI) induces activation in the right primary sensorimotor cortex and in supplementary motor areas, which are shown to lie posterior and medial to the lesion.

Oligodendroglioma, WHO grade II

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