Atypical teratoid rhabdoid tumor

9-month-old with pathologically proven atypical teratoid-rhabdoid tumor (ATRT). Transverse axial T2- (A), FLAIR (B), and T2*-weighted gradient echo (C) MRIs show a T2-isointense to hypointense mass in the inferior cerebellar hemisphere, which compresses the upper cervical cord, extends through the foramen Luschka, and is associated with enlargement of the left cerebello-medullary cistern (*). There are small, marginal T2- and FLAIR-hyperintense cystic foci (arrows) and punctate, hypointense foci of hemorrhage within the tumor on the T2*-weighted image. Heterogeneous contrast enhancement is demonstrated on transverse axial (E), sagittal (F), and coronal (G) postcontrast T1-weighted images compared with the precontrast T1-weighted image (D).