The patient went on to have a resection.

Histology

The sections show stellate reticulum-like epithelium, forming nests with peripheral palisading and loose stroma. There is associated wet keratin and dystrophic calcification. The epithelial cells show squamoid morphology with no nuclear atypia. There is no evidence of malignancy. A small amount of piloid gliosis is present. 

DIAGNOSIS: adamantinomatous craniopharyngioma.