FIG 2. Brain MR images obtained at the time of initial clinical presentation show peripheral enhancement of a mass in the right cerebral white matter that extends through the cerebral peduncle and into the right cerebellar hemisphere via the right middle cerebellar peduncle.

A, Coronal fluid-attenuated inversion recovery (TR/TE/TI, 8000/112/2700) image demonstrates marked adjacent vasogenic edema.

B, Coronal spin-echo gadolinium-enhanced T1-weighted image (TR/TE, 600/15).

C and D, Axial spoiled-gradient postcontrast T1-weighted images (9.2/2.0; flip angle, 20° at the level of the lateral ventricles [C] and middle cerebellar peduncle [D]).