A large peripherally enhancing mass right posterior parietal-occipital lobe. it shows uniform smooth peripheral  ring enhancement with central necrosis / fluid content. Marked peri tumoral edema with adjacent mild mass effect. Mild compression on occipital horn of right lateral ventricle. no midline shift.  No other enhancing lesion present in rest of brain parenchyma.
Findings consistent with  cystic Glioma / or cystic metastasis. 
Other differential includes abscess formation.   