Focal atrophy in the right parietal lobe with replacement by a cystic mass that communicates with the right lateral ventricle causing mass effect on the overlying skull vault leading it to be bowed out. It could be an arachnoid cyst but communicates with the ventricle thus the mass effect on the inner table of the vault by CSF pulsation. It is not open lip schizencephaly as the defect is not grey matter lined.