MRI
DWI
T1 C+ fat sat
T2
The periventricular burden of FLAIR signal abnormality has progressed. The left frontal biopsy tract is noted with residual haemosiderin staining evident. The periventricular enhancement is again demonstrated and largely stable. The right occipital lesion has shown a discrete change in morphological appearance with increasing mass effect and prominent thickening of the occipital cortex. The surrounding FLAIR signal abnormality remains largely unchanged, however the gyriform pattern of enhancement is far more intense. Extensive restricted diffusion.
Conclusion: The evolution of the right occipital lesion is difficult to reconcile with demyelination, or evolving infarction and an alternative diagnosis should be sought. The possibility of all these changes representing CNS lymphoma should be entertained.