. The patient did not return until about 10 weeks later, at which time he presented with a history significant for newly-diagnosed intermediate-grade non-Hodgkin's lymphoma. He had begun chemotherapy one month before the second examination at our clinic; methotrexate therapy for CNS metastasis had been provided at the time of the spinal taps. At the second visit, there was marked progression of the swelling of the left optic disk and mild swelling of the right disk