This is a difficult case, with the cerebellar lesion having unusual and non-specific appearances. A metastasis was considered most likely, especially in the setting of a lung mass, although even then appearances are atypical. The absence of diffusion restriction made pyogenic infections most unlikely. 

The patient went on to have a craniotomy. The lesion appeared filled with translucent white material. 

Histology confirmed the left cerebellar lesion as a cryptococcoma.