A hypodense or hyperdense lesion that enhances in a nodular, homogeneous, or ringlike pattern may be observed. Significant edema and mass effect may be present. Multiple lesions can occur, although less frequently than with toxoplasmosis. MRI may reveal additional lymphomatous lesions. Positive results need to be confirmed by biopsy of the identified lesion.
Histologic findings vary and comprise a small, noncleaved type and a large, immunoblastic type.
Radiation is a widely used treatment for CNS lymphoma. Adult dose is 4000-5000 cGy. This results in clinical improvement and radiographic regression of the lesions. Anecdotal reports are known of responses to systemic and intrathecal methotrexate, thiotepa, and procarbazine. No dosage recommendations can be given at this point.