Coronal view of an MRI scan (with contrast) of brain from a 3 y/o male (same case as previous image). There is a large cystic mass with a brightly enhancing mural nodule in the cerebellum. The location of the tumor, its appearance, and the patient age together are diagnostic of pilocytic astrocytoma. Most of the patients are children between 5 yrs. and 14 yrs. of age. Rare cases occur in adults. Case produced with permission, courtesy of Dr. Frank Gaillard. Radiopaedia. Complete case is here.