Left sided proptosis; history of left eyelid melanoma excision. Orbit: There is mild left proptosis associated with bowing of the posterolateral wall of the orbit secondary to an arachnoid cyst in the anterior portion of the left middle cranial fossa. Otherwise, there is no evidence of intraorbital mass lesions and the globes and ocular adnexa are intact. Brain: The arachnoid cyst in the anterior portion of the left middle cranial fossa measures up to 18 mm in width with associated remodeling of the overlying skull. There is no evidence of acute intracranial hemorrhage or abnormal enhancement. There is a 9 mm wide left choroid fissure cyst. The ventricles are otherwise normal in size and configuration. There is no midline shift or herniation. There is moderate right maxillary sinus mucosal thickening and a left sphenoid sinus retention cyst. There is minimal fluid signal in the right mastoid air cells.
Mild left proptosis associated with bowing of the posterolateral wall of the orbit secondary to an arachnoid cyst in the anterior portion of the left middle cranial fossa. No evidence of intraorbital or intracranial tumors otherwise. 