The peripherally enhancing lesion in the left cerebral peduncle is stable, with a focus of enhancement demonstrated extending into the left thalamus is again noted, but since the previous study, there has been decrease in extent of FLAIR hyperintensity, particularly adjacent to the trigone of the left lateral ventricle and in the left middle cerebellar peduncle extending into the anterior left cerebellar hemisphere.
Haemosiderin staining is again demonstrated, consistent with previous haemorrhage. There is a probable focus of elevated CBV within the left thalamus, corresponding to the focus of enhancement. Elsewhere, no convincing CBV elevation. MRS again demonstrates elevated choline and a lactate peak.Elevated T2 signal in the left inferior olivary nucleus probably represents non-enhancing tumour. Alternatively it may represent hypertrophic olivary degeneration.
Conclusion
Slight decrease in size of bulkiness of FLAIR hyperintensity suggests evolution of pseudoprogression seen on the prior study, although no doubt residual tumour is present and some co-existing tumour growth may be present.