Metastatic lung cancer. There are numerous, at least 40, new enhancing lesions with associated mild vasogenic edema in the brain and cerebellum, primarily distributed at the grey-white matter junctions. The largest lesion measures up to 25 mm in the right temporal stem and appears to be cystic or necrotic. Many of the lesions also demonstrate susceptibility effect. There is no evidence of acute infarct. There are unchanged mild nonspecific punctate foci of high T2 signal in the cerebral white matter. There is an unchanged arachnoid cyst in the anterior right posterior fossa that measures up to 12 mm in width with associated mild mass effect upon the right cerebellar hemisphere. The ventricles and basal cisterns are stable in size and configuration. There is no midline shift or herniation. There is a right maxillary sinus retention cyst. The skull appears to be intact.
Numerous hemorrhagic intracranial metastases.