colloid cyst
A benign developmental cyst lined by ciliated epithelium, typically located in the third ventricle at the foramen of Monro.
Full Definition
A colloid cyst is a benign, developmental cyst that most commonly occurs in the third ventricle at the level of the foramen of Monro. These cysts are lined by a single layer of ciliated cuboidal to columnar epithelium and contain proteinaceous material that appears gelatinous or colloid-like. The cyst wall may show chronic inflammatory changes and calcification. Despite their benign nature, colloid cysts can cause acute hydrocephalus due to CSF flow obstruction at the foramen of Monro, potentially leading to sudden death. The epithelial lining typically expresses cytokeratins and may show mucin production.
Usage
Usage note: Location at foramen of Monro is characteristic; can cause life-threatening acute hydrocephalus.
In Context
- "The third ventricular cyst showed ciliated epithelium and proteinaceous contents characteristic of colloid cyst." — Neuropathology report
- "Emergency surgery was required for colloid cyst causing acute obstructive hydrocephalus." — Neurosurgical case report