A large area of FLAIR hyperintensity involving both cortex and white matter is seen within the left frontal lobe, extending into the insular cortex and anterior temporal lobe. Abnormal signal just extends into the medial temporal structures on the left. No definite signal abnormality in the right anterior temporal lobe, although minor abnormality is not excluded with the amount of artefact present. Ill-defined areas of mild relative hyperdensity on the CT (not shown) at the anterior aspect of the FLAIR abnormality corresponds to subtle T2 hypointensity, with mild diffusion restriction, relative elevated CBV and equivocal mild enhancement, although there is a tiny focus of faint enhancement just adjacent to the anterior horn of the left lateral ventricle. Spectroscopy demonstrates decreased NAA and small lipid/lactate peaks with no definite significant elevated choline allowing for poor baseline. The lesion exerts moderate mass effect, with 5 mm of subfalcine herniation at the level of the septum pellucidum. There is mild effacement of the left lateral ventricle.
Conclusion: Large left frontotemporal abnormality involving both white matter and cortex produces moderate mass-effect as described. This most likely to represents a diffuse glioma.