Abstract
An 80-year-old woman presented with primary central nervous system (CNS) lymphoma manifesting as progressive disorientation and loss of activity. She received three cycles of high-dose methotrexate. The tumor shrank after two cycles and her mental status improved, but she suffered tumor recurrence. The second-line treatment consisted of four cycles of rituximab but the tumor enlarged. She was then treated with three cycles of temozolomide. Magnetic resonance imaging revealed no evidence of disease. Her mental status and performance status improved, and she suffered no toxicity. She is able to pursue her daily life without recurrence after 16 cycles of temozolomide. Temozolomide may be effective against relapsed primary CNS lymphoma without causing neurotoxicity in the elderly.