porencephalic cyst
Pronunciation: /ˌpɔːrənˌsɛfəˈlɪk/
A fluid-filled cavity in the brain parenchyma that communicates with the ventricular system or subarachnoid space, usually resulting from prior injury or malformation.
Full Definition
Porencephalic cysts are cerebrospinal fluid-filled cavities within the brain parenchyma that maintain communication with either the ventricular system or subarachnoid space. These lesions can be congenital (true porencephaly) resulting from developmental abnormalities, or acquired (false porencephaly) following brain injury such as infarction, hemorrhage, or infection. In pediatric neuroradiology, porencephalic cysts appear as well-defined, CSF-intensity lesions on all MRI sequences, with smooth walls and no enhancement. The surrounding brain parenchyma may show gliosis or volume loss. Clinical presentations vary depending on size and location, ranging from asymptomatic findings to seizures, developmental delays, or focal neurological deficits. Differentiation from other cystic brain lesions requires careful attention to imaging characteristics and clinical history.
Usage
Usage note: Distinguish between congenital (true) and acquired (false) types for accurate classification.
In Context
- "The large porencephalic cyst communicated with the right lateral ventricle on MRI." — Pediatric brain MRI report
- "Acquired porencephalic cyst formation followed the neonatal stroke in the left MCA territory." — Neurodevelopmental follow-up imaging