A 65-year-old patient presented to the emergency room with cognitive deficits, including increased forgetfulness and decreased speed of speech and mobility for the past few days.

The patient was initially thought to present symptoms of cerebrovascular accident and underwent initial CT head that demonstrated a mixed-density partially calcified suprasellar mass lesion extending to the anterior third ventricle, causing obstruction of the foramen of Monroe and secondary hydrocephalus. MRI confirmed the presence of a mass lesion and the main preoperative diagnosis was a craniopharyngioma.

The lesion also shared several characteristics with a colloid cyst, including high attenuation content on unenhanced CT and secondary obstruction with acute hydrocephalus. However, the presence of calcification and pattern of extension to the suprasellar cistern made this diagnosis less likely.  

The patient underwent surgical resection of the lesion.

Histology

Sections reveal trabecular bone with the fibrotic bone marrow mostly with “wet” keratin debris. There is also wet keratin associated with marked piloid gliosis and small fragments of normal-appearing anterior pituitary. There is no viable neoplastic epithelium identified. 
Conclusion: findings are compatible with craniopharyngioma, adamantinomatous type. 

Post-surgical imaging showed immediate improvement of the acute hydrocephalus.

The case was contributed by Dr Raquel Delcarpio, Associate Professor of Radiology at McGill University.