Central nervous system lymphoma.

The imaging diagnosis of CNS lymphoma is challenging because of the multiplicity of compartments that it may present in or spread to, the variety of imaging manifestations that may be produced, and the fact that the clinical picture may not focus the clinician or radiologist on the correct diagnosis. However, recent strides in diagnostic imaging made not only with CT but now with MR allow recognition of tumor spread that was not possible before. Examples to support this statement are the noninvasive recognition of cord compression on MR, the demonstration of intraspinal and intracranial leptomeningeal tumor spread, and the improved demonstration of subdural tumor deposits.