To the Editor.
—We were intrigued by the observations of Bennett et al concerning the computed tomographic (CT) appearance of systemic malignant lymphoma involving the brain (Archives 1983;40:187-188). The authors suggested that these rare lesions appear either as solitary or multiple enhancing lesions or a pattern of linear subependymal or meningeal enhancement. It would be incorrect, however, to infer that CNS lymphoma is manifested exclusively in this manner. Lymphomatous deposits can also appear as isodense areas with focal enhancement, areas of edema with or without focal enhancement, intracerebral or subdural hemorrhage with or without an area of unusually early adjacent edema, or an unusual pattern of gyral or meningeal enhancement.The basis of these relatively non-specific signs has been described previously.1 Areas of radiolucency, with or without intrinsic adjacent edema, can represent either a primary deposit of lymphoma in the brain or areas of damage to otherwise normal