Choroid plexus papilloma status post resection: surveillance. There are postoperative findings related to midline suboccipital craniotomy and resection of the posterior arch of C1. There is a persistent subcentimeter nodular focus of enhancement within the right cerebellomedullary angle. The lesion abuts the right vertebral artery. There is also subcentimeter patchy enhancement within the fourth ventricle. There is a right transparietal ventricular catheter which courses from the occipital horn of the lateral ventricle and terminates within the body of the lateral ventricle, indenting upon the cavum septum pellucidum. There is no significant change in size of the ventricular system. There is also interval resolution of bilateral subdural fluid collections and decreased diffuse smooth dural enhancement. There is no evidence of acute infarction. There is an unchanged mildly prominent and partially cystic pineal gland that measures up to 10 mm, which may be physiologic in nature. The major cerebral flows voids are grossly intact. There is fluid within the right mastoid air cells. The orbits are unremarkable.
1. Persistent subcentimeter foci of enhancement within the right cerebellomedullary angle and fourth ventricle, which may represent residual tumor and/or treatment effects. 2. Unchanged appearance of the shunted ventricular system, but resolution of the mild bilateral cerebral convexity subdural effusions.3. Fluid within the right mastoid air cells may represent mastoiditis. 