Atypical teratoid rhabdoid tumor (AT/RT)

A large mass in the right lobe, with mass effect and central low density. The lesion is slightly hyperdense peripherally to gray matter. There is surrounding vasogenic edema as well. 

A large, heterohenous, mainly high T2 and low T1, mass centered in the right basal ganglia with significant positive mass effect on the ipsilateral sulci and lateral ventricle and midline shift to the left. Surrounded by a large area of white matter T2/FLAIR hyperinntensity, most in keeping with vasogenic edema. The mass exhibits heterogenous contrast enhancement, with a non enhancing center, consistent with necrosis. A large cystic component is also seen inferiorly.