Pilocytic astrocytoma

A large, relatively well-circumscribed, mass lesion is seen involving the right cerebellum in this 3-year old child. There is marked compression of the fourth ventricle and midbrain, with midline shift. There is a large solid enhancing component medially, with a cystic component laterally and enhancement as well of the cyst wall. Note that the cystic portion of the lesion is easily differentiated from both normal CSF and the solid portion of the lesion on the coronal FLAIR exam.

Pilocytic astrocytoma

Part of the on-line supplement to Neuroradiology – The Essentials with MR and CT (© 2015)