The appearances of those of primary CNS lymphoma.

Although a previous history of lymphoma is indicated no intercurrent disease was present ( in remission ) at the time of this study.

The pattern of disease involving the deep white matter and corpus callosum is more typical than the leptomeningeal disease typically identified in secondary CNS lymphoma.

The case also illustrates the striking superiority of MRI in imaging the brain - the extensive deep white matter disease is essentially unidentifiable on the CT brain.