Primary CNS lymphoma with recent biopsy showing monomorphic post-transplant lymphoproliferative disorder, status post MTX therapy. There are interval left transparietal biopsy findings. There is decreased patchy T2 hyperintensity in the left parietal and right temporal lobe white matter and no evidence of residual enhancing lesions in the brain. Otherwise, there are unchanged scattered foci of cerebral white matter T2 hyperintensity, but no evidence of acute infarct. The ventricles and basal cisterns are normal in size and configuration. There is no midline shift or herniation. The major cerebral flow voids are intact. The orbits are grossly unremarkable. There is cosmetic filler material in the bilateral nasolabial fold regions.
Interval regression of the brain lesions, indicating treatment response.