MRI T2WI, Sagittal SectionA large extra-axial, well-defined CSF intensity cystic lesion is identified in the midline in the sellar and suprasellar region. It measures 48 x 62 x 47 mm in AP transverse and cranio-caudal dimension. This lesion is causing a compressive effect on the third ventricle and bilateral lateral ventricles. These findings are consistent with arachnoid cyst.MRI T2WI: magnetic resonance imaging T2 weighted image; CSF: cerebrospinal fluid.