CNS lymphoma and Omaya now with visual hallucinations. There is increased patchy T2 hyperintensity and mild patchy enhancement in the right basal ganglia region with extension along the margin of the right frontal horn, measuring up to approximately 35 mm, previously approximately 20 mm. There is also persistent infiltrative abnormal enhancement involving the left optic nerve. However, abnormality along the bilateral cerebellar tonsils is no longer discernible. There are unchanged nonspecific foci of T2 hyperintensity without corresponding enhancement in the cerebral white matter. There is no evidence of acute infarction or intracranial hemorrhage. There is a right transfrontal Ommaya catheter that terminates in the right lateral ventricle, near the right foramen of Monro. There is no midline shift or herniation. There is right maxillary sinus mucosal thickening and an apparent fluid level in the left maxillary sinus. There is also mild fluid signal within the mastoid air cells bilaterally. There are multiple adenoidal mucous retention cysts.
1. Further increase in size of an infiltrative lesion in the right basal ganglia region with patchy enhancement along the margin of the right frontal horn likely represents involvement by lymphoma. 2. Apparent persistent enhancement of the left optic nerve may also represent involvement by lymphoma, although the images are not optimized for orbital imaging.3. Persistent findings suggestive of acute sinusitis.