Primary CNS lymphoma status post treatment. There are post-treatment findings in the left frontal lobe with unchanged areas of patchy T2 hyperintensity with scattered susceptibility effect and mild ex vacuo dilatation of left frontal horn. There are also unchanged foci of high T2 signal in the right anterior frontal lobe. However, there is a new area of enhancement measuring up to 12 mm with surrounding vasogenic edema involving the right inferior frontal gyrus. There is no evidence of acute infarct. There is no midline shift or herniation. The major cerebral flow voids are intact. The orbits, skull, paranasal sinuses, and scalp soft tissues are unchanged.
A new area of enhancement with surrounding vasogenic edema involving the right inferior frontal gyrus likely represents recurrent lymphoma. Otherwise, unchanged post-treatment findings in the left frontal lobe.