Porencephalic Cyst true A congenital or acquired cystic cavity within the cerebral hemisphere. Porencephalic Cyst C99020 C4082172 Finding Porencephalic cysts are cavities seen in the cerebral hemispheres, that may arise due to past hypoxia-ischemia, vascular occlusion (stroke), haemorrhage, or infection. These cysts may co-exist with other structural sequelae of the original cerebral insult or with hippocampal sclerosis. Porencephalic Cyst NICHD Cystic area of encephalomalacia that is the end result of a destructive process such as intraparenchymal hemorrhage, infection or trauma. Porencephalic Cyst structural etiology