Fig. 21.

A 5-year-old girl with headaches and vomiting referred with a posterior fossa mass. a, b Pre- (a) and post-contrast (b) axial computed tomography images show an intermediate density mass with peripheral enhancement involving the left cerebellar peduncle and cerebellar hemisphere and complicated by hydrocephalus. c, d Axial magnetic resonance images (MRI). The mass is profoundly hypointense on T2 (c) and shows no diffusion restriction (d). e Magnetic resonance spectroscopy shows  a lactate peak (arrow). f Axial post-gadolinium T1 MRI shows central intermediate intensity and peripheral enhancement. These imaging features are characteristic of a tuberculoma—there was response to anti-tuberculous treatment