What are the most likely diagnosis in this case? Which are the important differentials to be considered?
This case seems to correspond to a RCC metastasis. Differentials to a cerebral ring enhancing are broad and include GBM and abscess.
Selected images of the brain demonstrating a right frontal lobe mass characterised by an spontaneous hyperdense rim with a vivid contrast enhancement and a central hypodense area (necrotic?). This lesion has a local mass effect with vasogenic oedema and mild anterior mediline shift.