The patient went on to have a resection. 

Histology

Paraffin sections show several fragments of an adamantinomatous craniopharyngioma. These consist of irregularly shaped islands of epithelium with prominent peripheral basaloid cell layers, a central squamous epithelium with focal keratinization and intermediate stellate reticulum. No mitotic figures or areas of necrosis are identified. Adjacent brain parenchyma shows well-developed piloid gliosis with numerous Rosenthal fibers identified.

DIAGNOSIS: adamantinomatous craniopharyngioma.

Characteristic imaging features of adamantinomatous craniopharyngioma, although the age of presentation is unusual (peak presentation age for this subtype is 10-14 years).