Male, 41 years old, with history of grade II oligodendroglioma, follow-up examination . Sequelae of prior resection are seen with cavities involving the right anterior temporal lobe and the inferior right frontal lobe. Findings related to more recent right frontal approach stereotactic biopsy are also seen.Since the prior examination, significant progression of irregularly marginated enhancement is seen within the right frontal lobe. The lesion now measuring up to 48 x 35 mm in the axial plane, whereas enhancement in this location on the prior examination was subcentimeter in size. This enhancement extends superiorly along the prior frontal lobe biopsy tract.Internally, this lesion demonstrates smudgy susceptibility compatible with blood product along with patchy restricted diffusion. On rCBV mapping, there are scattered patches of elevated blood volume within this large enhancing lesion, though there is an equal proportion of tissue which shows relatively low blood volume. Patchy enhancement is also seen within the right genu of the corpus callosum, within the right insula and inferior frontal gyrus, and along the ependyma of the right ventricular atrium.Along with progressive enhancement, there has been a significant increase in the degree of surrounding FLAIR hyperintensity and generalized regional mass effect. The right lateral ventricle is partially effaced, as are the regional sulci, and there is a new midline shift to the left of approximately 5 mm.No lesions are seen in the left cerebral hemisphere. Likewise, the brainstem and cerebellum are relatively spared. No evidence of brain herniation is seen. No acute intracranial hemorrhage is suspected.
Extensive progressive enhancement, FLAIR signal abnormality and mass effect is seen within the right frontal lobe, above the level of prior resections. Progressive enhancement is also seen within the genu of the corpus callosum, the right insula and inferior frontal lobe, and along the ependyma of the right ventricular atrium. Morphologically, these findings are highly suggestive of progressive tumor. In particular, the discontiguous involvement of the corpus callosum and the progressive ependymal enhancement would be atypical for a treatment related effect. The finding of low blood volume in portions of the dominant frontal lobe lesion would be somewhat at odds with pure progressive tumor, though it could be seen in the context of mixed tumor and treatment effect.